medical_specialty atrial fibrillation
Medicine ( British English ; American English ) is the science and practice of the diagnosis , treatment , and prevention of disease . The word " medicine " is derived from Latin " medicus ", meaning " a physician ". Medicine encompasses a variety of health care practices evolved to maintain and restore health by the prevention and treatment of illness . Contemporary medicine applies biomedical sciences , biomedical research , ___MASK19___ , and medical technology to diagnose , treat , and prevent injury and disease , typically through pharmaceuticals or surgery , but also through therapies as diverse as psychotherapy , external splints and traction , medical devices , biologics , and ionizing radiation , amongst others . Hydrocephalus is a condition in which there is an abnormal accumulation of cerebrospinal fluid ( CSF ) within the brain . This typically causes increased pressure inside the skull . Older people may have headaches , double vision , poor balance , urinary incontinence , personality changes , or mental impairment . In babies there may be a rapid increase in head size . Other symptoms may include vomiting , sleepiness , seizures , and downward pointing of the eyes . Hydrocephalus can occur due to birth defects or be acquired later in life . Associated birth defects include neural tube defects and those that result in aqueductal stenosis . Other causes include meningitis , brain tumors , traumatic brain injury , intraventricular hemorrhage , and subarachnoid hemorrhage . There are four types of hydrocephalus : communicating , non - communicating , ex - vacuo , and normal pressure . Diagnosis is typically by examination and medical imaging . Hydrocephalus is typically treated by the surgical placement of a shunt system . A procedure called a third ventriculostomy may be an option in a few people . Complications from shunts may include overdrainage , underdrainage , mechanical failure , ___MASK69___ , or obstruction . This may require replacement . Outcomes are variable ; however , many live normal lives . Without treatment death may occur . About one to two per 1 , 000 newborns have hydrocephalus . Rates in the developing world may be more . Normal pressure hydrocephalus is estimated to affect about 5 per 100 , 000 people with rates increasing with age . Description of hydrocephalus by Hippocrates date back more than 2000 years . The word " hydrocephalus " is . Pneumonia is an inflammatory condition of the lung affecting primarily the microscopic air sacs known as alveoli . Typical signs and symptoms include a varying severity and combination of productive or dry cough , chest pain , fever , and trouble breathing , depending on the underlying cause . Pneumonia is usually caused by ___MASK69___ with viruses or bacteria and less commonly by other microorganisms , certain medications and conditions such as autoimmune diseases . Risk factors include other lung diseases such as cystic fibrosis , COPD , and asthma , diabetes , heart failure , a history of smoking , a poor ability to cough such as following a stroke , or a weak immune system . Diagnosis is often based on the symptoms and physical examination . Chest X - ray , blood tests , and culture of the sputum may help confirm the diagnosis . The disease may be classified by where it was acquired with community , hospital , or health care associated pneumonia . Vaccines to prevent certain types of pneumonia are available . Other methods of prevention include handwashing and not smoking . Treatment depends on the underlying cause . Pneumonia believed to be due to bacteria is treated with antibiotics . If the pneumonia is severe , the affected person is generally hospitalized . Oxygen therapy may be used if oxygen levels are low . Pneumonia affects approximately 450 million people globally ( 7 % of the population ) and results in about 4 million deaths per year . Pneumonia was regarded by William Osler in the 19th century as " the captain of the men of death ". With the introduction of antibiotics and vaccines in the 20th century , survival improved . Nevertheless , in developing countries , and among the very old , the very young , and the chronically ill , pneumonia remains a leading cause of death . Pneumonia often shortens suffering among those already close to death and has thus been called " the old man ' s friend ". Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body . Not all tumors are cancerous ; benign tumors do not spread to other parts of the body . Possible signs and symptoms include a lump , abnormal bleeding , prolonged cough , unexplained weight loss and a change in bowel movements . While these symptoms may indicate cancer , they may have other causes . Over 100 types of cancers affect humans . Tobacco use is the cause of about 22 % of cancer deaths . Another 10 % is due to obesity , poor diet , lack of physical activity and drinking alcohol . Other factors include certain infections , exposure to ionizing radiation and environmental pollutants . In the developing world nearly 20 % of cancers are due to infections such as hepatitis B , hepatitis C and human papillomavirus ( HPV ). These factors act , at least partly , by changing the genes of a cell . Typically many genetic changes are required before cancer develops . Approximately 5  10 % of cancers are due to inherited genetic defects from a person ' s parents . Cancer can be detected by certain signs and symptoms or screening tests . It is then typically further investigated by medical imaging and confirmed by biopsy . Many cancers can be prevented by not smoking , maintaining a healthy weight , not drinking too much alcohol , eating plenty of vegetables , fruits and whole grains , vaccination against certain infectious diseases , not eating too much processed and red meat , and avoiding too much sunlight exposure . Early detection through screening is useful for cervical and colorectal cancer . The benefits of screening in breast cancer are controversial . Cancer is often treated with some combination of radiation therapy , ___MASK63___ , chemotherapy , and targeted therapy . Pain and symptom management are an important part of care . Palliative care is particularly important in people with advanced disease . The chance of survival depends on the type of cancer and extent of disease at the start of treatment . In children under 15 at diagnosis the five - year survival rate in the developed world is on average 80 %. For cancer in the United States the average five - year survival rate is 66 %. In 2012 about 14 . 1 million new cases of cancer occurred globally ( not including skin cancer other than melanoma ). It caused about 8 . 2 million deaths or 14 . 6 % of human deaths . The most common types of cancer in males are lung cancer , prostate cancer , colorectal cancer and stomach cancer . In females , the most common types are breast cancer , colorectal cancer , lung cancer and cervical cancer . If skin cancer other than melanoma were included in total new cancers each year it would account for around 40 % of cases . In children , acute lymphoblastic leukaemia and brain tumors are most common except in Africa where non - Hodgkin lymphoma occurs more often . In 2012 , about 165 , 000 children under 15 years of age were diagnosed with cancer . The risk of cancer increases significantly with age and many cancers occur more commonly in developed countries . Rates are increasing as more people live to an old age and as lifestyle changes occur in the developing world . The financial costs of cancer were estimated at $ 1 . 16 trillion US dollars per year as of 2010 . Definitions . Cancers are a large family of diseases that involve abnormal cell growth with the potential to invade or spread to other parts of the body . They form a subset of neoplasms . A neoplasm or tumor is a group of cells that have undergone unregulated growth and will often form a mass or lump , but may be distributed diffusely . Medical imaging is the technique and process of creating visual representations of the interior of a body for clinical analysis and medical intervention , as well as visual representation of the function of some organs or tissues ( physiology ). Medical imaging seeks to reveal internal structures hidden by the skin and bones , as well as to diagnose and treat disease . Medical imaging also establishes a database of normal anatomy and physiology to make it possible to identify abnormalities . Although imaging of removed organs and tissues can be performed for medical reasons , such procedures are usually considered part of ___MASK36___ instead of medical imaging . Osteoarthritis ( OA ) is a type of joint disease that results from breakdown of joint cartilage and underlying bone . The most common symptoms are joint pain and stiffness . Initially , symptoms may occur only following exercise , but over time may become constant . Other symptoms may include joint swelling , decreased range of motion , and when the back is affected weakness or numbness of the arms and legs . The most commonly involved joints are those near the ends of the fingers , at the base of the thumb , neck , lower back , knee , and hips . Joints on one side of the body are often more affected than those on the other . Usually the symptoms come on over years . It can affect work and normal daily activities . Unlike other types of arthritis , only the joints are typically affected . Causes include previous joint injury , abnormal joint or limb development , and inherited factors . Risk is greater in those who are overweight , have one leg of a different length , and have jobs that result in high levels of joint stress . Osteoarthritis is believed to be caused by mechanical stress on the joint and low grade inflammatory processes . It develops as cartilage is lost and the underlying bone becomes affected . As pain may make it difficult to exercise , muscle loss may occur . Diagnosis is typically based on signs and symptoms , with medical imaging and other tests occasionally used to either support or rule out other problems . In contrast to rheumatoid arthritis , which is primarily an inflammatory condition , in osteoarthritis , the joints do not typically become hot or red . Treatment includes exercise , efforts to decrease joint stress , support groups , and pain medications . Efforts to decrease joint stress include resting and the use of a cane . Weight loss may help in those who are overweight . Pain medications may include paracetamol ( acetaminophen ) as well as NSAIDs such as naproxen or ibuprofen . Long - term opioid use is generally discouraged due to lack of information on benefits as well as risks of addiction and other side effects . If pain interferes with normal life despite other treatments , joint replacement ___MASK63___ may help . An artificial joint typically lasts 10 to 15 years . Osteoarthritis is the most common form of arthritis with disease of the knee and hip affecting about 3 . 8 % of people as of 2010 . Among those over 60 years old , about 10 % of males and 18 % of females are affected . It is the cause of about 2 % of years lived with disability . In Australia , about 1 . 9 million people are affected , and in the United States , 30 to 52 . 5 million people are affected . It becomes more common in both sexes as people become older . Dementia , also known as senility , is a broad category of brain diseases that cause a long term and often gradual decrease in the ability to think and remember that is great enough to affect a person ' s daily functioning . Other common symptoms include emotional problems , problems with language , and a decrease in motivation . A person ' s consciousness is usually not affected . A dementia diagnosis requires a change from a person ' s usual mental functioning and a greater decline than one would expect due to aging . These diseases also have a significant effect on a person ' s caregivers . The most common type of dementia is Alzheimer ' s disease , which makes up 50 % to 70 % of cases . Other common types include vascular dementia ( 25 %), Lewy body dementia ( 15 %), and frontotemporal dementia . Less common causes include normal pressure hydrocephalus , Parkinson ' s disease , syphilis , and Creutzfeldt  Jakob disease among others . More than one type of dementia may exist in the same person . A small proportion of cases run in families . In the DSM - 5 , dementia was reclassified as a neurocognitive disorder , with various degrees of severity . Diagnosis is usually based on history of the illness and cognitive testing with medical imaging and blood work used to rule out other possible causes . The mini mental state examination is one commonly used cognitive test . Efforts to prevent dementia include trying to decrease risk factors such as high blood pressure , smoking , diabetes , and obesity . Screening the general population for the disorder is not recommended . There is no cure for dementia . Cholinesterase inhibitors such as donepezil are often used and may be beneficial in mild to moderate disorder . Overall benefit , however , may be minor . For people with dementia and those who care for them many measures can improve their lives . Cognitive and behavioral interventions may be appropriate . Educating and providing emotional support to the caregiver is important . Exercise programs may be beneficial with respect to activities of daily living and potentially improve outcomes . Treatment of behavioral problems with antipsychotics is common but not usually recommended due to the little benefit and side effects , including an increased risk of death . Globally , dementia affects 47 . 5 million people . About 10 % of people develop the disorder at some point in their lives . It becomes more common with age . About 3 % of people between the ages of 65  74 have dementia , 19 % between 75 and 84 and nearly half of those over 85 years of age . In 2013 dementia resulted in about 1 . 7 million deaths up from 0 . 8 million in 1990 . As more people are living longer , dementia is becoming more common in the population as a whole . For people of a specific age , however , it may be becoming less frequent , at least in the developed world , due to a decrease in risk factors . It is one of the most common causes of disability among the old . It is believed to result in economic costs of 604 billion USD a year . People with dementia are often physically or chemically restrained to a greater degree than necessary , raising issues of human rights . Social stigma against those affected is common . Obesity is a medical condition in which excess body fat has accumulated to the extent that it may have a negative effect on health . People are generally considered obese when their body mass index ( BMI ), a measurement obtained by dividing a person ' s weight by the square of the person ' s height , is over , with the range defined as overweight . Some East Asian countries use lower values . Obesity increases the likelihood of various diseases , particularly heart disease , type 2 diabetes , obstructive sleep apnea , certain types of cancer , and osteoarthritis . Obesity is most commonly caused by a combination of excessive food intake , lack of physical activity , and genetic susceptibility . A few cases are caused primarily by genes , endocrine disorders , medications , or mental illness . The view that obese people eat little yet gain weight due to a slow metabolism is not generally supported . On average , obese people have a greater energy expenditure than their thin counterparts due to the energy required to maintain an increased body mass . Obesity is mostly preventable through a combination of social changes and personal choices . Changes to diet and exercising are the main treatments . Diet quality can be improved by reducing the consumption of energy - dense foods , such as those high in fat and sugars , and by increasing the intake of dietary fiber . Medications may be taken , along with a suitable diet , to reduce appetite or decrease fat absorption . If diet , exercise , and medication are not effective , a gastric balloon or ___MASK63___ may be performed to reduce stomach volume or bowel length , leading to feeling full earlier or a reduced ability to absorb nutrients from food . Obesity is a leading preventable cause of death worldwide , with increasing rates in adults and children . In 2014 , 600 million adults ( 13 %) and 42 million children under the age of five were obese . Obesity is more common in women than men . Authorities view it as one of the most serious public health problems of the 21st century . Obesity is stigmatized in much of the modern world ( particularly in the Western world ), though it was seen as a symbol of wealth and fertility at other times in history and still is in some parts of the world . In 2013 , the American Medical Association classified obesity as a disease . Rheumatic fever ( RF ), also known as acute rheumatic fever ( ARF ), is an inflammatory disease that can involve the heart , joints , skin , and brain . The disease typically develops two to four weeks after a streptococcal throat ___MASK69___ . Signs and symptoms include fever , multiple painful joints , involuntary muscle movements , and occasionally a characteristic non - itchy rash known as erythema marginatum . The heart is involved in about half of cases . Damage to the heart valves , known as rheumatic heart disease ( RHD ), usually occurs after repeated attacks but can sometimes occur after one . The damaged valves may result in heart failure , atrial fibrillation and ___MASK69___ of the valves . Rheumatic fever may occur following an ___MASK69___ of the throat by the bacterium " Streptococcus pyogenes ". If the ___MASK69___ is untreated rheumatic fever can occur in up to three percent of people . The underlying mechanism is believed to involve the production of antibodies against a person ' s own tissues . Due to their ___MASK19___ , some people are more likely to get the disease when exposed to the bacteria than others . Other risk factors include malnutrition and poverty . Diagnosis of RF is often based on the presence of signs and symptoms in combination with evidence of a recent streptococcal ___MASK69___ . Treating people who have strep throat with antibiotics , such as penicillin , decreases the risk of developing rheumatic fever . In order to avoid antibiotic misuse this often involves testing people with sore throats for the ___MASK69___ , which may not be available in the developing world . Other preventive measures include improved sanitation . In those with rheumatic fever and rheumatic heart disease , prolonged periods of antibiotics are sometimes recommended . Gradual return to normal activities may occur following an attack . Once RHD develops , treatment is more difficult . Occasionally valve replacement surgery or valve repair is required . Otherwise complications are treated as per normal . Rheumatic fever occurs in about 325 , 000 children each year and about 18 million people currently have rheumatic heart disease . Those who develop RF are most often between the ages of 5 and 14 , with 20 % of first - time attacks occurring in adults . The disease is most common in the developing world and among indigenous peoples in the developed world . In 2013 it resulted in 275 , 000 deaths down from 374 , 000 deaths in 1990 . Most deaths occur in the developing world where as many as 12 . 5 % of people affected may die each year . Descriptions of the condition are believed to date back to at least the 5th century BCE in the writings of Hippocrates . The disease is so named because its symptoms are similar to those of some rheumatic disorders . Thyroid disease is a medical condition that affects the function of the thyroid gland ( the endocrine organ found at the front of the neck that produces thyroid hormones ). The symptoms of thyroid disease vary depending on the type . There are four general types : 1 ) hypothyroidism ( low function ) caused by not having enough thyroid hormones , ( 2 ) hyperthyroidism ( high function ) caused by having too much thyroid hormones , 3 ) structural abnormalities , most commonly an enlargement of the thyroid gland , 3 ) tumors which can be benign or cancerous , and 4 ) abnormal thyroid function tests without any clinical symptoms . Common hypothyroid symptoms include fatigue , low energy , weight gain , inability to tolerate the cold , slow heart rate , dry skin and constipation . Common hyperthyroid symptoms include irritability , weight loss , fast heartbeat , heat intolerance , diarrhea , and enlargement of the thyroid . In both hypothyroidism and hyperthyroidism , there may be swelling of a part of the neck , which is also known as goiter . Diagnosis can often be made through laboratory tests . The first is thyroid - stimulating hormone ( TSH ), which is generally below normal in hyperthyroidism and above normal in hypothyroidism . The other useful laboratory test is non - protein - bound thyroxine or free T4 . Total and free triiodothyronine ( T3 ) levels are less commonly used . Anti - thyroid autoantibodies can also be used , where elevated anti - thyroglobulin and anti - thyroid peroxidase antibodies are commonly found in hypothyroidism from Hashimoto ' s thyroiditis and TSH - receptor antibodies are found in hyperthyroidism caused by Graves ' disease . Procedures such as ultrasound , biopsy and a radioiodine scanning and uptake study may also be used to help with the diagnosis . Treatment of thyroid disease varies based on the disorder . Levothyroxine is the mainstay of treatment for people with hypothyroidism , while people with hyperthyroidism caused by Graves ' disease can be managed with iodine therapy , antithyroid medication , or surgical removal of the thyroid gland . Thyroid ___MASK63___ may also be performed to remove a thyroid nodule or lobe for biopsy , or if there is a goiter that is unsightly or obstructs nearby structures . Hypothyroidism affects 3 - 10 % percent of adults , with a higher incidence in women and the elderly . An estimated one - third of the world ' s population currently lives in areas of low dietary iodine levels , making iodine - deficiency the most common cause of hypothyroidism and endemic goiter . In regions of severe iodine deficiency , the prevalence of goiter is as high as 80 %. In areas where iodine - deficiency is not found , the most common type of hypothyroidism is an autoimmune subtype called Hashimoto ' s thyroiditis , with a prevalence of 1 - 2 %. As for hyperthyroidism , Graves ' disease , another autoimmune condition , is the most common type with a prevalence of 0 . 5 % in males and 3 % in females . Although thyroid nodules are common , thyroid cancer is rare . Thyroid cancer accounts for less than 1 % of all cancer in the UK , though it is the most common endocrine tumor and makes up greater than 90 % of all cancers of the endocrine glands . Sleep apnea , also spelled sleep apnoea , is a sleep disorder characterized by pauses in breathing or periods of shallow breathing during sleep . Each pause can last for a few seconds to several minutes and they happen many times a night . In the most common form , this follows loud snoring . There may be a choking or snorting sound as breathing resumes . As it disrupts normal sleep , those affected are often sleepy or tired during the day . In children it may cause problems in school or hyperactivity . There are three forms of sleep apnea : obstructive ( OSA ), central ( CSA ), and a combination of the two called mixed . OSA is the most common form . Risk factors for OSA include being overweight , a family history of the condition , allergies , and enlarged tonsils . In OSA , breathing is interrupted by a blockage of airflow , while in CSA breathing stops due to a lack of effort to breathe . People with sleep apnea are often not aware they have it . Often it is first observed by a family member . Sleep apnea is often diagnosed with an overnight sleep study . For a diagnosis of sleep apnea , more than five episodes an hour must occur . Treatment may include lifestyle changes , mouthpieces , breathing devices , and ___MASK63___ . Lifestyle changes may include avoiding alcohol , weight loss , stopping smoking , and sleeping on their side . Breathing devices include the use of a CPAP machine . Without treatment sleep apnea may increase the risk of heart attack , stroke , diabetes , heart failure , irregular heartbeat , obesity , and motor vehicle collisions . OSA affects 1 - 6 % of adults and 2 % of children . It affects males about twice as often as females . While people at any age can be affected it occurs most commonly among those 55 to 60 years old . Central sleep apnea affects less than one percent of people . A type of central sleep apnea was described in the German myth of Ondine ' s curse where when asleep the person would forget to breathe . Signs and symptoms . People with sleep apnea have problems with excessive daytime sleepiness ( EDS ), impaired alertness , and vision problems . OSA may increase risk for driving accidents and work - related accidents . If OSA is not treated , people are at increased risk of other health problems , such as diabetes . Even death could occur from untreated OSA due to lack of oxygen to the body . Moreover , people are examined using " standard test batteries " in order to further identify parts of the brain that may be adversely affected by sleep apnea , including those that govern : ___MASK69___ is the invasion of an organism ' s body tissues by disease - causing agents , their multiplication , and the reaction of host tissues to these organisms and the toxins they produce . Infectious disease , also known as transmissible disease or communicable disease , is illness resulting from an ___MASK69___ . Infections are caused by infectious agents including viruses , viroids , prions , bacteria , nematodes such as parasitic roundworms and pinworms , arthropods such as ticks , mites , fleas , and lice , fungi such as ringworm , and other macroparasites such as tapeworms and other helminths . Atrial fibrillation ( AF or A - fib ) is an abnormal heart rhythm characterized by rapid and irregular beating . Often it starts as brief periods of abnormal beating which become longer and possibly constant over time . Most episodes have no symptoms . Occasionally there may be heart palpitations , fainting , shortness of breath , or chest pain . The disease increases the risk of heart failure , dementia , and stroke . It is a type of supraventricular tachycardia . Hypertension and valvular heart disease are the most common alterable risk factors for AF . Other heart - related risk factors include heart failure , coronary artery disease , cardiomyopathy , and congenital heart disease . In the developing world valvular heart disease often occurs as a result of rheumatic fever . Lung - related risk factors include COPD , obesity , and sleep apnea . Other factors include excess alcohol intake , diabetes mellitus , and thyrotoxicosis . However , half of cases are not associated with one of these risks . A diagnosis is made by feeling the pulse and may be confirmed using an electrocardiogram ( ECG ) . The typical ECG shows no P waves and an irregular ventricular rate . AF is often treated with medications to slow the heart rate to a near normal range ( known as rate control ) or to convert the rhythm to normal sinus rhythm ( known as rhythm control ) . Electrical cardioversion can also be used to convert AF to a normal sinus rhythm and is often used emergently if the person is unstable . Ablation may prevent recurrence in some people . Depending on the risk of stroke either aspirin or anti - clotting medications such as warfarin or a novel oral anticoagulant may be recommended . While these medications reduce this risk , they increase rates of major bleeding . Atrial fibrillation is the most common serious abnormal heart rhythm . In Europe and North America , as of 2014 , it affects about 2 % to 3 % of the population . This is an increase from 0 . 4 to 1 % of the population around 2005 . In the developing world about 0 . 6 % of males and 0 . 4 % of females are affected . The percentage of people with AF increases with age with 0 . 14 % under 50 years old , 4 % between 60 and 70 years old , and 14 % over 80 years old being affected . A - fib and atrial flutter resulted in 112 , 000 deaths in 2013 , up from 29 , 000 in 1990 . The first known report of an irregular pulse was by Jean - Baptiste de Sénac in 1749 . This was first documented by ECG in 1909 by Thomas Lewis . Syphilis is a sexually transmitted ___MASK69___ caused by the bacterium " Treponema pallidum " subspecies " pallidum ". The signs and symptoms of syphilis vary depending in which of the four stages it presents ( primary , secondary , latent , and tertiary ). The primary stage classically presents with a single chancre ( a firm , painless , non - itchy skin ulceration ) but there may be multiple sores . In secondary syphilis a diffuse rash occurs , which frequently involves the palms of the hands and soles of the feet . There may also be sores in the mouth or vagina . In latent syphilis , which can last for years , there are few or no symptoms . In tertiary syphilis there are gummas ( soft non - cancerous growths ), neurological , or heart symptoms . Syphilis has been known as " the great imitator " as it may cause symptoms similar to many other diseases . Syphilis is most commonly spread through sexual activity . It may also be transmitted from mother to baby during pregnancy or at birth , resulting in congenital syphilis . Other human diseases caused by related " Treponema pallidum " subspecies include yaws ( subspecies " pertenue "), pinta ( subspecies " carateum "), and bejel ( subspecies " endemicum "). Diagnosis is usually made by using blood tests ; the bacteria can also be detected using dark field microscopy . The Center for Disease Control recommends all pregnant women be tested . The risk of syphilis can be decreased by latex condom use , or not having sex . Syphilis can be effectively treated with antibiotics . The preferred antibiotic for most cases is benzathine penicillin G injected into a muscle . In those who have a severe penicillin allergy , doxycycline or tetracycline may be used . In those with neurosyphilis , intravenous penicillin G potassium or ceftriaxone is recommended . During treatment people may develop fever , headache , and muscle pains , a reaction known as Jarisch - Herxheimer . In 2012 , about 0 . 5 % of adults were infected with syphilis with 6 million new cases . During 2010 , it caused about 113 , 000 deaths , down from 202 , 000 in 1990 . After decreasing dramatically with the availability of penicillin in the 1940s , rates of ___MASK69___ have increased since the turn of the millennium in many countries , often in combination with human immunodeficiency virus ( HIV ). This is believed to be partly due to increased promiscuity , prostitution , decreasing use of condoms , and unsafe sexual practices among men who have sex with men . In 2015 , Cuba became the first country in the world to eliminate mother - to - child transmission of syphilis . Signs and symptoms . Syphilis can present in one of four different stages : primary , secondary , latent , and tertiary , and may also occur congenitally . It was referred to as " the great imitator " by Sir William Osler due to its varied presentations . Malnutrition or malnourishment is a condition that results from eating a diet in which nutrients are either not enough or are too much such that the diet causes health problems . It may involve calories , protein , carbohydrates , vitamins or minerals . Not enough nutrients is called undernutrition or undernourishment while too much is called overnutrition . Malnutrition is often used specifically to refer to undernutrition where there is not enough calories , protein , or micronutrients . If undernutrition occurs during pregnancy , or before two years of age , it may result in permanent problems with physical and mental development . Extreme undernourishment , known as starvation , may have symptoms that include : a short height , thin body , very poor energy levels , and swollen legs and abdomen . People also often get infections and are frequently cold . The symptoms of micronutrient deficiencies depend on the micronutrient that is lacking . Undernourishment is most often due to not enough high - quality food being available to eat . This is often related to high food prices and poverty . A lack of breastfeeding may contribute , as may a number of infectious diseases such as : gastroenteritis , pneumonia , malaria , and measles , which increase nutrient requirements . There are two main types of undernutrition : protein - energy malnutrition and dietary deficiencies . Protein - energy malnutrition has two severe forms : marasmus ( a lack of protein and calories ) and kwashiorkor ( a lack of just protein ). Common micronutrient deficiencies include : a lack of iron , iodine , and vitamin A . During pregnancy , due to the body ' s increased need , deficiencies may become more common . In some developing countries , overnutrition in the form of obesity is beginning to present within the same communities as undernutrition . Other causes of malnutrition include anorexia nervosa and bariatric ___MASK63___ . Efforts to improve nutrition are some of the most effective forms of development aid . Breastfeeding can reduce rates of malnutrition and death in children , and efforts to promote the practice increase the rates of breastfeeding . In young children , providing food ( in addition to breastmilk ) between six months and two years of age improves outcomes . There is also good evidence supporting the supplementation of a number of micronutrients to women during pregnancy and among young children in the developing world . To get food to people who need it most , both delivering food and providing money so people can buy food within local markets are effective . Simply feeding students at school is insufficient . Management of severe malnutrition within the person ' s home with ready - to - use therapeutic foods is possible much of the time . In those who have severe malnutrition complicated by other health problems , treatment in a hospital setting is recommended . This often involves managing low blood sugar and body temperature , addressing dehydration , and gradual feeding . Routine antibiotics are usually recommended due to the high risk of ___MASK69___ . Longer - term measures include : improving agricultural practices , reducing poverty , improving sanitation , and the empowerment of women . There were 793 million undernourished people in the world in 2015 ( 13 % of the total population ). This is a reduction of 216 million people since 1990 when 23 % were undernourished . In 2012 it was estimated that another billion people had a lack of vitamins and minerals . In 2013 , protein - energy malnutrition was estimated to have resulted in 469 , 000 deaths  down from 510 , 000 deaths in 1990 . Other nutritional deficiencies , which include iodine deficiency and iron deficiency anemia , result in another 84 , 000 deaths . In 2010 , malnutrition was the cause of 1 . 4 % of all disability adjusted life years . About a third of deaths in children are believed to be due to undernutrition , although the deaths are rarely labelled as such . In 2010 , it was estimated to have contributed to about 1 . 5 million deaths in women and children , though some estimate the number may be greater than 3 million . An additional 165 million children were estimated to have stunted growth from malnutrition in 2013 . Undernutrition is more common in developing countries . Certain groups have higher rates of undernutrition , including women  in particular while pregnant or breastfeeding  children under five years of age , and the elderly . In the elderly , undernutrition becomes more common due to physical , psychological , and social factors . In medicine , a pulse represents the tactile arterial palpation of the heartbeat by trained fingertips . The pulse may be palpated in any place that allows an artery to be compressed against a bone , such as at the neck ( carotid artery ), on the inside of the elbow ( brachial artery ), at the wrist ( radial artery ), at the groin ( femoral artery ), behind the knee ( popliteal artery ), near the ankle joint ( posterior tibial artery ), and on foot ( dorsalis pedis artery ). Pulse ( or the count of arterial pulse per minute ) is equivalent to measuring the heart rate . The heart rate can also be measured by listening to the heart beat directly ( auscultation ), traditionally using a stethoscope and counting it for a minute . The radial pulse is commonly measured using three fingers . This has a reason : the finger closest to the heart is used to occlude the pulse pressure , the middle finger is used get a crude estimate of the blood pressure , and the finger most distal to the heart ( usually the ring finger ) is used to nullify the effect of the ulnar pulse as the two arteries are connected via the palmar arches ( superficial and deep ). The study of the pulse is known as sphygmology . Myocardial infarction ( MI ) or acute myocardial infarction ( AMI ), commonly known as a heart attack , occurs when blood flow stops to a part of the heart causing damage to the heart muscle . The most common symptom is chest pain or discomfort which may travel into the shoulder , arm , back , neck , or jaw . Often it is in the center or left side of the chest and lasts for more than a few minutes . The discomfort may occasionally feel like heartburn . Other symptoms may include shortness of breath , nausea , feeling faint , a cold sweat , or feeling tired . About 30 % of people have atypical symptoms , with women more likely than men to present atypically . Among those over 75 years old , about 5 % have had an MI with little or no history of symptoms . An MI may cause heart failure , an irregular heartbeat ( including serious types ), cardiogenic shock , or cardiac arrest . Most MIs occur due to coronary artery disease . Risk factors include high blood pressure , smoking , diabetes , lack of exercise , obesity , high blood cholesterol , poor diet , and excessive alcohol intake , among others . The mechanism of an MI often involves the complete blockage of a coronary artery caused by a rupture of an atherosclerotic plaque . MIs are less commonly caused by coronary artery spasms , which may be due to cocaine , significant emotional stress , and extreme cold , among others . A number of tests are useful to help with diagnosis , including electrocardiograms ( ECGs ), blood tests , and coronary angiography . An ECG may confirm an ST elevation MI if ST elevation is present . Commonly used blood tests include troponin and less often creatine kinase MB . Aspirin is an appropriate immediate treatment for a suspected MI . Nitroglycerin or opioids may be used to help with chest pain ; however , they do not improve overall outcomes . Supplemental oxygen should be used in those with low oxygen levels or shortness of breath . In ST elevation MIs treatments which attempt to restore blood flow to the heart are typically recommended and include angioplasty , where the arteries are pushed open , or thrombolysis , where the blockage is removed using medications . People who have a non - ST elevation myocardial infarction ( NSTEMI ) are often managed with the blood thinner heparin , with the additional use of angioplasty in those at high risk . In people with blockages of multiple coronary arteries and diabetes , bypass ___MASK63___ ( CABG ) may be recommended rather than angioplasty . After an MI , lifestyle modifications , along with long term treatment with aspirin , beta blockers , and statins , are typically recommended . Worldwide , about 8 . 6 million myocardial infarctions occurred in 2013 . More than 3 million people had an ST elevation MI and more than 4 million had an NSTEMI . STEMIs occur about twice as often in men as women . About one million people have an MI each year in the United States . In the developed world the risk of death in those who have had an STEMI is about 10 %. Rates of MI for a given age have decreased globally between 1990 and 2010 . A ventricular assist device ( VAD ) is an electromechanical device for assisting cardiac circulation , which is used either to partially or to completely replace the function of a failing heart . The function of VADs is different from that of artificial cardiac pacemakers ; some are for short - term use , typically for patients recovering from myocardial infarction ( heart attack ) and for patients recovering from cardiac ___MASK63___ ; some are for long - term use ( months to years to perpetuity ), typically for patients suffering from advanced congestive heart failure . Hyperthyroidism is the condition that occurs due to excessive production of thyroid hormone by the thyroid gland . Thyrotoxicosis is the condition that occurs due to excessive thyroid hormone of any cause and therefore includes hyperthyroidism . Some , however , use the terms interchangeably . Signs and symptoms vary between people and may include irritability , muscle weakness , sleeping problems , a fast heartbeat , heat intolerance , diarrhea , enlargement of the thyroid , and weight loss . Symptoms are typically less in the old and during pregnancy . An uncommon complication is thyroid storm in which an event such as an ___MASK69___ results in worsening symptoms such as confusion and a high temperature and often results in death . The opposite is hypothyroidism , when the thyroid gland does not make enough thyroid hormone . Graves ' disease is the cause of about 50 % to 80 % of the cases of hyperthyroidism in the United States . Other causes include multinodular goiter , toxic adenoma , inflammation of the thyroid , eating too much iodine , and too much synthetic thyroid hormone . A less common cause is a pituitary adenoma . The diagnosis may be suspected based on signs and symptoms and then confirmed with blood tests . Typically blood tests show a low thyroid stimulating hormone ( TSH ) and raised T or T . Radioiodine uptake by the thyroid , thyroid scan , and TSI antibodies may help determine the cause . Treatment depends partly on the cause and severity of disease . There are three main treatment options : radioiodine therapy , medications , and thyroid surgery . Radioiodine therapy involves taking iodine - 131 by mouth which is then concentrated in and destroys the thyroid over weeks to months . The resulting hypothyroidism is treated with synthetic thyroid hormone . Medications such as beta blockers may control the symptoms , and anti - thyroid medications such as methimazole may temporarily help people while other treatments are having effect . Surgery to remove the thyroid is another option . This may be used in those with very large thyroids or when cancer is a concern . In the United States hyperthyroidism affects about 1 . 2 % of the population . It occurs between two and ten times more often in women . Onset is commonly between 20 and 50 years of age . Overall the disease is more common in those over the age of 60 years . In epidemiology , a risk factor is a variable associated with an increased risk of disease or ___MASK69___ . Sometimes , determinant is also used , being a variable associated with either increased or decreased risk . Heart failure ( HF ), often referred to as congestive heart failure ( CHF ), occurs when the heart is unable to pump sufficiently to maintain blood flow to meet the body ' s needs . Signs and symptoms commonly include shortness of breath , excessive tiredness , and leg swelling . The shortness of breath is usually worse with exercise , while lying down , and may wake the person at night . A limited ability to exercise is also a common feature . Chest pain , including angina , does not typically occur due to heart failure . Common causes of heart failure include coronary artery disease including a previous myocardial infarction ( heart attack ), high blood pressure , atrial fibrillation , valvular heart disease , excess alcohol use , ___MASK69___ , and cardiomyopathy of an unknown cause . These cause heart failure by changing either the structure or the functioning of the heart . There are two main types of heart failure : " heart failure due to left ventricular dysfunction " and " heart failure with normal ejection fraction " depending on whether the ability of the left ventricle to contract is affected , or the heart ' s ability to relax . The severity of disease is usually graded by the degree of problems with exercise . Heart failure is not the same as myocardial infarction ( in which part of the heart muscle dies ) or cardiac arrest ( in which blood flow stops altogether ). Other diseases that may have symptoms similar to heart failure include obesity , kidney failure , liver problems , anemia , and thyroid disease . The condition is diagnosed based on the history of the symptoms and a physical examination with confirmation by echocardiography . Blood tests , electrocardiography , and chest radiography may be useful to determine the underlying cause . Treatment depends on the severity and cause of the disease . In people with chronic stable mild heart failure , treatment commonly consists of lifestyle modifications such as stopping smoking , physical exercise , and dietary changes , as well as medications . In those with heart failure due to left ventricular dysfunction , angiotensin converting enzyme inhibitors or angiotensin receptor blockers along with beta blockers are recommended . For those with severe disease , aldosterone antagonists , or hydralazine with a nitrate may be used . Diuretics are useful for preventing fluid retention . Sometimes , depending on the cause , an implanted device such as a pacemaker or an implantable cardiac defibrillator may be recommended . In some moderate or severe cases cardiac resynchronization therapy ( CRT ) may be suggested or cardiac contractility modulation may be of benefit . A ventricular assist device or occasionally a heart transplant may be recommended in those with severe disease despite all other measures . Heart failure is a common , costly , and potentially fatal condition . In developed countries , around 2 % of adults have heart failure and in those over the age of 65 , this increases to 6  10 %. In the year after diagnosis the risk of death is about 35 % after which it decreases to below 10 % each year . This is similar to the risks with a number of types of cancer . In the United Kingdom the disease is the reason for 5 % of emergency hospital admissions . Heart failure has been known since ancient times with the Ebers papyrus commenting on it around 1550 BCE . Parkinson ' s disease ( PD ) is a long - term degenerative disorder of the central nervous system that mainly affects the motor system . The symptoms generally come on slowly over time . Early in the disease , the most obvious are shaking , rigidity , slowness of movement , and difficulty with walking . Thinking and behavioral problems may also occur . Dementia becomes common in the advanced stages of the disease . Depression and anxiety are also common occurring in more than a third of people with PD . Other symptoms include sensory , sleep , and emotional problems . The main motor symptoms are collectively called " parkinsonism ", or a " parkinsonian syndrome ". The cause of Parkinson ' s disease is generally unknown , but believed to involve both genetic and environmental factors . Those with a family member affected are more likely to get the disease themselves . There is also an increased risk in people exposed to certain pesticides and among those who have had prior head injuries while there is a reduced risk in tobacco smokers and those who drink coffee or tea . The motor symptoms of the disease result from the death of cells in the substantia nigra , a region of the midbrain . This results in not enough dopamine in these areas . The reason for this cell death is poorly understood , but involves the build - up of proteins into Lewy bodies in the neurons . Diagnosis of typical cases is mainly based on symptoms , with tests such as neuroimaging being used to rule out other diseases . There is no cure for Parkinson ' s disease . Initial treatment is typically with the antiparkinson medication L - DOPA ( levodopa ), with dopamine agonists being used once levodopa becomes less effective . As the disease progresses and neurons continue to be lost , these medications become less effective while at the same time they produce a complication marked by involuntary writhing movements . Diet and some forms of rehabilitation have shown some effectiveness at improving symptoms . ___MASK63___ to place microelectrodes for deep brain stimulation has been used to reduce motor symptoms in severe cases where drugs are ineffective . Evidence for treatments for the non - movement - related symptoms of PD , such as sleep disturbances and emotional problems , is less strong . In 2013 , PD was present in 53 million people and resulted in about 103 , 000 deaths globally . Parkinson ' s disease typically occurs in people over the age of 60 , of which about one percent are affected . Males are more often affected than females . When it is seen in people before the age of 40 or 50 , it is called young onset PD . The average life expectancy following diagnosis is between 7 and 14 years . The disease is named after the English doctor James Parkinson , who published the first detailed description in " An Essay on the Shaking Palsy ", in 1817 . Public awareness campaigns include World Parkinson ' s Day ( on the birthday of James Parkinson , 11 April ) and the use of a red tulip as the symbol of the disease . People with parkinsonism who have increased the public ' s awareness of the condition include actor Michael J . Fox , Olympic cyclist Davis Phinney , and late professional boxer Muhammad Ali . Supraventricular tachycardia ( SVT ) is an abnormally fast heart rhythm arising from improper electrical activity in the upper part of the heart . There are four main types : atrial fibrillation , paroxysmal supraventricular tachycardia ( PSVT ), atrial flutter , and Wolff - Parkinson - White syndrome . Symptoms may include palpitations , feeling faint , sweating , shortness of breath , or chest pain . They start from either the atria or atrioventricular node . They are generally due to one of two mechanisms : re - entry or increased automaticity . The other type of fast heart rhythm is ventricular arrhythmias  rapid rhythms that start within the ventricle . Diagnosis is typically by electrocardiogram ( ECG ), holter monitor , or event monitor . Blood tests may be done to rule out specific underlying causes such as hyperthyroidism or electrolyte abnormalities . Specific treatments depend on the type of SVT . They can include medications , medical procedures , or ___MASK63___ . Vagal maneuvers or a procedure known as catheter ablation may be effective in certain types . For atrial fibrillation calcium channel blockers or beta blockers may be used . Long term some people benefit from blood thinners such as aspirin or warfarin . Atrial fibrillation affects about 25 per 1000 people , paroxysmal supraventricular tachycardia 2 . 3 per 1000 , Wolff - Parkinson - White syndrome 2 per 1000 , and atrial flutter 0 . 8 per 1000 . Electrocardiography ( ECG or EKG *) is the process of recording the electrical activity of the heart over a period of time using electrodes placed on the skin . These electrodes detect the tiny electrical changes on the skin that arise from the heart muscle ' s electrophysiologic pattern of depolarizing during each heartbeat . It is a very commonly performed ___MASK86___ test . Stroke is when poor blood flow to the brain results in cell death . There are two main types of stroke : ischemic , due to lack of blood flow , and hemorrhagic , due to bleeding . They result in part of the brain not functioning properly . Signs and symptoms of a stroke may include an inability to move or feel on one side of the body , problems understanding or speaking , feeling like the world is spinning , or loss of vision to one side . Signs and symptoms often appear soon after the stroke has occurred . If symptoms last less than one or two hours it is known as a transient ischemic attack ( TIA ) or mini - stroke . A hemorrhagic stroke may also be associated with a severe headache . The symptoms of a stroke can be permanent . Long - term complications may include pneumonia or loss of bladder control . The main risk factor for stroke is high blood pressure . Other risk factors include tobacco smoking , obesity , high blood cholesterol , diabetes mellitus , previous TIA , and atrial fibrillation . An ischemic stroke is typically caused by blockage of a blood vessel , though there are also less common causes . A hemorrhagic stroke is caused by either bleeding directly into the brain or into the space between the brain ' s membranes . Bleeding may occur due to a ruptured brain aneurysm . Diagnosis is typically with medical imaging such as a CT scan or magnetic resonance imaging ( MRI ) scan along with a physical exam . Other tests such as an electrocardiogram ( ECG ) and blood tests are done to determine risk factors and rule out other possible causes . Low blood sugar may cause similar symptoms . Prevention includes decreasing risk factors , as well as possibly aspirin , statins , ___MASK63___ to open up the arteries to the brain in those with problematic narrowing , and warfarin in those with atrial fibrillation . A stroke or TIA often requires emergency care . An ischemic stroke , if detected within three to four and half hours , may be treatable with a medication that can break down the clot . Aspirin should be used . Some hemorrhagic strokes benefit from ___MASK63___ . Treatment to try recover lost function is called stroke rehabilitation and ideally takes place in a stroke unit ; however , these are not available in much of the world . In 2013 approximately 6 . 9 million people had an ischemic stroke and 3 . 4 million people had a hemorrhagic stroke . In 2010 there were about 33 million people who had previously had a stroke and were still alive . Between 1990 and 2010 the number of strokes which occurred each year decreased by approximately 10 % in the developed world and increased by 10 % in the developing world . In 2013 , stroke was the second most frequent cause of death after coronary artery disease , accounting for 6 . 4 million deaths ( 12 % of the total ). About 3 . 3 million deaths resulted from ischemic stroke while 3 . 2 million deaths resulted from hemorrhagic stroke . About half of people who have had a stroke live less than one year . Overall , two thirds of strokes occurred in those over 65 years old .