Obstructive sleep apnea (OSA) is suggested by several physical features or signs that can be seen, observed or measured. Usually noted during a doctor’s physical exam these sleep apnea signs can signal or contribute to upper airway narrowing or airway collapse during sleep.
Snoring & other noises during sleep
Snoring, especially loud snoring is one of the most common signs of sleep apnea. Most people with sleep apnea snore, but not everyone who snores has sleep apnea. Other noises during sleep are often described as snorting, gasping or coughing. Sometimes, the absence of noise during sleep may indicate a pause to breathing that is also a sleep apnea sign.
Sleep apnea signs
Sleep apnea signs that reduce airway caliber include obesity, a large neck size, enlarged tonsils, or a large tongue. A physical exam can uncover features of disorders associated with a narrowed airway. It might also detect the presence of medical conditions correlated with sleep apnea, such as high blood pressure.
Obesity is a well known sleep apnea sign. Obesity increases the risk of sleep apnea and may signal its presence when present together with symptoms like excessive sleepiness or snoring. Doctors can assess excess weight by measuring height, weight, and calculating a body mass index or by calculating a waist circumference. The area where excess fat or weight accumulates in an individual may play a role in whether apnea develops or not. Different measurements help quantify this distribution. Central obesity, determined by the distance around one’s waist shows the degree of fat depositing around the abdomen. Since it correlates with fat around the upper airway, it is perhaps the most predictive sleep apnea sign, heralding the risk for the development of obstructive sleep apnea. BMI is another popular measurement that has been to assess obesity, another sleep apnea sign. Due to its ease of measurment, population studies have tracked BMI more frequently than central obesity. BMI is a ratio of weight to height. The actual equation is Weight (kg)/ height2 (in meters). Studies show that as BMI increases above 28, so does the risk for sleep apnea. At a BMI of 30 or grater the occurrence of OSA is 20% to 40%. At a BMI of greater than 40 there is a 40% likelihood of sleep apnea or another form of sleep disordered breathing. This increases to 50% at a BMI greater than 50.
Crowding of airway and large necks
Crowding of the upper airway and large neck size are two sleep apnea signs commonly inspected by sleep medicine doctors to assess the risk of sleep apnea. Seen on physical exam, a crowded airway is a frequently seen sleep apnea sign on physical exam. It may result from normal faciocranial anatomy or an individuals upper airway anatomy–even if they are not overweight. This sleep apnea sign can also result from excess fat deposition around the airway. Deposition of fat in the area surrounding the airway may result in a large neck size. This can be easily determined by checking collar size or measuring the neck. A circumference of greater than 17 inches (43 cm) in men or 16 inches (41 cm) in women is associated with sleep apnea. Other sleep apnea signs include a deviated septum, enlarged tonsils or a low lying soft palate that contribute to crowding of the upper airway. Careful inspection of the nose can show nasal blockages or a deviated septum contributing to limited airflow. Inspection inside the mouth may reveal enlarged tonsils or a low lying soft palate that also crowd the airway, leading to airway narrowing and apnea. Several scales such as the Mallampati Score and the Friedman Classification have developed to document how crowded the airway looks on a scale from 1 to 4.
High blood pressure can be identified on exam and is present in a high degree of patients with sleep apnea. Nearly 50% of patients with hypertension have OSA. Similarly, a large population study of over six thousand individuals looking at the risk of HTN in normal patients compared to patients with severe sleep apnea reported an odds ratio of 1.37 even after adjusting for age and BMI. In patients with uncontrolled high blood pressure the relationship is stronger. One study showed that approximately 83% of patients with high blood pressure uncontrolled by life style changes or medications also had OSA.
Physical signs of Thyroid disease
A thorough inspection may reveal problems with the thyroid gland that can lead to OSA. The thyroid is an organ in the lower half of the neck that regulates the body’s metabolism. Hypothyroidism results from low levels of thyroid hormone. Patients with hypothyroidism have slowed metabolism and swelling that may narrow the airway. Slowed metabolism also leads to excess weight gain worsening apnea. The thyroid itself can also become enlarged for various reasons. This enlargement, known commonly as a goiter, can potentially put pressure on the airway.
Diseases leading to abnormal structure
A constellation of physical findings may be seen in conditions such as Down Syndrome or acromegaly. People with Down Syndrome, a genetic disorder, have several features including flattening of their facial structure, low muscle tone, enlarged tongue and tonsils and airway development abnormalities that contribute to the risk of sleep apnea. Similarly, patients with acromegaly often have enlarged tongues, facial bones and soft tissue around airways due to growth hormone excess.
Diseases leading to protein deposition
A few other disorders such as amyloidosis and mucopolysaccharidosis also lead to sleep apnea through protein deposition around the muscles of the airway. Amyloidosis and mucopolysaccharidosis are two medical conditions that cause abnormal deposits of proteins throughout the body. Amyloidosis is the development of abnormal proteins in body organs and tissues. Mucopolysaccharidosis is a condition where the body cannot break down large proteins into smaller ones. This causes a buildup of proteins throughout the body including around the airway.
In summary, conditions that lead to a narrowed airway contribute to the development of sleep apnea. The features of a narrowed airway can often be seen directly on inspection. Other times, characteristics of disorders that correlate with sleep apnea can be seen on exam.