How common are headaches in adults?
Headache is one of the most common and debilitating pain conditions in the world. According to the World Health Organization, almost half of the adults in the world have had a headache in the past year. The World Health Organization also names headache the third leading cause of disability in the world and the number one cause of disability in individuals under the age of 50.
Headaches are a major cause of absenteeism from work and school. They also cause a heavy personal toll in terms of social life, family life, and anxiety and depression due to fear of the next headache. Headaches affect people of all races, ages, and geographical location.
What are the types of headaches?
A comprehensive headache classification guide was established by the International Headache Society and includes more than 150 headache categories.
Based on research, a practical headache classification divides headaches into two main categories primary and secondary headaches.
Primary headaches are those that are not the result of another medical condition. The category includes tension-type, migraine, and cluster headaches.
- Tension-type headaches are the most common type of headache. Tension-type headaches tend to be mild to moderate, non-throbbing, and occur on both sides of the head (bilateral). They usually do not get worse during routine activities (bending over, walking stairs, etc.) Because tension-type headaches tend to be mild, patients usually treat them successfully with over-the-counter medications. Patients should be aware that using over-the-counter medications too often can lead to long term (chronic) daily headache.
- Migraines are the second most common type of primary headaches. The exact cause of migraines is unknown, although they are caused by changes in the nerves and blood vessels. Migraines are also related to changes in the brain and inherited abnormalities in certain areas of the brain. Migraine pain is moderate to severe, often described as pounding or throbbing. Migraines can last from 4 hours to 3 days and usually occur less than 15 times per month. Migraine symptoms include sensitivity to light, noise or odors; nausea or vomiting; loss of appetite; and stomach upset or abdominal pain.
- Cluster headaches are the most severe, type of primary headache. The pain of a cluster headache is intense and has a burning or stabbing quality that is throbbing or constant. The pain is so severe that most patients with cluster headache cannot sit still and will often pace during an attack. The pain is located behind one eye or in the eye region, without changing sides. The term “cluster headache” refers to headaches that come in a group, or cluster. Cluster headaches occur one to eight times per day during a cluster period, which may last 2 weeks to 3 months. The headaches may disappear completely (go into "remission") for months or years, only to recur.
- New daily persistent headaches (NDPH) start abruptly as a headache that is new to the patient. The patient is able to pinpoint the brief period of time (within 72 hour) when the headache appeared. While these headaches may not be related to other diseases, they tend to be constant or persistent without any remission, located on both sides of the head (bilateral), and don’t respond to many medications.
Secondary headaches, or those that result from another medical or neurological condition, include sinus headaches, medication overuse headaches, or headaches that occur because of an infection, disease of the blood vessels in the brain, head injury, trauma, or more serious condition such as a tumor.
- Sinus headaches are associated with a deep and constant pain in the cheekbones, forehead, or bridge of the nose. The pain usually gets worse with sudden head movement or straining and occurs with other acute sinus symptoms, such as nasal discharge, foul taste in the mouth, a feeling of fullness in the ears, fever, facial swelling, and pain over the involved sinus.
- Medication overuse headaches occur as a result of the overuse of either readily available over-the-counter analgesics or prescribed painkillers such as opiates and sedative hypnotic tablets designed for headache management (butalbital-containing headache remedies). This is among the most common type of chronic headache seen in specialty headache centers and is referred to as a “transformed” headache. Tension-type or migraine headaches that recur can transform into a chronic headache from the inappropriate “overuse” of medications. These headaches can also happen without the overuse of analgesics. It is believed that 4 percent of the population worldwide has chronic daily headaches of some type, and a good percentage of this population includes headaches caused from medication overuse.
Are headaches hereditary?
Yes, headaches, especially migraines, have a tendency to run in families. Children who have migraines usually have at least one parent who also suffers from the condition. Headaches also can be triggered by certain environmental factors that are shared in a family’s household, such as:
- Second-hand tobacco smoke
- Strong odors from household chemicals or perfumes
- Exposure to certain allergens
- Eating certain foods
Stress, pollution, noise, lighting, and weather changes are other environmental factors that can trigger headaches for some people.
People with migraines may inherit abnormalities in certain areas of the brain, as well as the tendency to be affected by certain migraine triggers, such as fatigue, bright lights, weather changes, and others.
What causes headaches?
Headache pain results from signals interacting among the brain, blood vessels, and surrounding nerves. During a headache, specific nerves of the blood vessels are activated and send pain signals to the brain. It’s not clear, however, why these signals are activated in the first place.
There is a migraine “pain center,” or generator, in the mid-brain area. A migraine begins when overactive nerve cells send out impulses to the blood vessels. This causes the release of prostaglandins, serotonin, and other substances that cause swelling of the blood vessels in the vicinity of the nerve endings, resulting in pain.
Headaches that occur suddenly (acute onset) are usually caused by an illness, infection, cold, or fever. Other conditions that can cause an acute headache include sinusitis (inflammation of the sinuses), pharyngitis (inflammation or infection of the throat), or otitis (ear infection or inflammation).
In some cases, the headaches may be the result of a blow to the head (trauma) or, rarely, a sign of a more serious medical condition.
Common triggers of tension-type headaches or migraine headaches include:
- Emotional stress related to family and friends, work, or school
- Alcohol use
- Skipping meals
- Changes in sleep patterns
- Excessive medication use
Other causes of headaches include eye strain and neck or neck and back strain caused by poor posture.
When headaches become progressive and occur along with other neurological symptoms, they can be the sign of a disease process in the brain, such as:
- Hydrocephalus (abnormal buildup of fluid in the brain)
- Meningitis (an infection or inflammation of the membrane that covers the brain and spinal cord)
- Encephalitis (infection/inflammation of the brain)
- Hemorrhage (bleeding within the brain)
- Blood clots along the surface of the brain
- Head trauma
- Toxins (overexposure to chemicals, including certain medications)