Epidemiology, history, definitions, and common symptoms

Sleep apnea is a potentially serious and even life-threatening condition that affects up to 18 million Americans according to the National Institutes of Health. Despite its high prevalence, it is often overlooked and undiagnosed. Although sleep apnea was described in ancient Hebrew texts, by William Shakespeare in Falstaff, and by Charles Dickens in The Pickwick Papers, the first contemporary medical description of sleep apnea was only published in 1965. In adolescents and adults, an apnea during sleep is defined as the absence of air flow through the nose and mouth for 10 seconds or more. During non-obstructive apneas, there is no breathing effort either because the brain or spinal cord fails to send an adequate signal to the breathing muscles or because there is a problem with the muscles or nerves that normally convey messages from the brain and spinal cord. Sleep apnea with predominantly non-obstructive apneas tends to be most common in the elderly however, it may occur at any age. Obstructive apneas are characterized by the absence of airflow for more than ten seconds despite ongoing breathing effort. During inhalation the upper airway is sucked closed, typically in the area behind the tongue. Sleep apnea with predominant obstructive apneas is most frequent in preadolescents, adolescents, and young and middle-aged adults.

Individuals with sleep apnea syndrome may have many apneas per hour of sleep. Partial breaths called hypopneas, like apneas lasting 10 seconds or more, may occur. They have the same consequences as apneas. 

Serious consequences

Untreated sleep apnea can increase the likelihood of critical medical consequences, such as irregular heartbeat, high blood pressure, heart failure, heart attack, and stroke. In addition, difficulty maintaining vigilant attention, organizing and executing tasks, and remembering can occur.


A majority of people with predominantly obstructive sleep apnea are overweight or obese. The severity of the apnea in these individuals is often proportionate to the degree of their obesity. However, people who are not overweight can also have obstructive sleep apnea. Common symptoms of obstructive sleep apnea, aside from excessive sleepiness, include loud snoring, headaches, heart burn, cognitive impairment, and awakening unrefreshed. Choking, coughing, excessive movement, regurgitation, and, in a small proportion of individuals, awakenings triggered by involuntary closure of the vocal cords, may occur. Patients with obstructive sleep apnea often awaken with a dry mouth and, in some cases, headaches. Breathing interruptions disrupt sleep and contribute to the excessive sleepiness that is a cardinal symptom of sleep apnea syndrome. In addition to being overweight, many patients with obstructive sleep apnea have high blood pressure, a recessed chin, or narrow or shallow upper airway. Obstructive sleep apnea tends to run in families.

Patients with obstructive sleep apnea and other conditions that cause chronic excessive sleepiness often tend to underestimate their degree of sleepiness. Family members or other observers often provide more accurate assessments of the patient's sleepiness. Individuals with obstructive apnea often believe their sleep is uninterrupted. Their sleep however, is usually interrupted by awakenings that are so brief that the patients are unaware of them. 

A care provider who is aware of the symptoms and signs of sleep apnea may suspect the diagnosis from the history and examination of the patient. Unfortunately, other physicians may miss the diagnosis. For this reason and because patients with apnea often do not complain to their doctors about their sleep-related symptoms, the majority of patients go undiagnosed and untreated. If the diagnosis is suspected most patients should complete an overnight recording of their sleep in a qualified sleep laboratory. Brain and muscle activity, eye movements, heart rate and rhythm, breathing effort, air flow, and blood oxygen levels are routinely recorded. A test the next day, called a multiple sleep latency test (MSLT), is sometime necessary to investigate other disorders that may mimic or compound sleep apnea. During the MSLT, sleep is recorded during four or five brief nap opportunities. While normal individuals fall asleep after an average of 10 to 20 minutes, people likely to benefit from treatment for underlying sleep problems are likely to fall asleep in less than five minutes.


All patients with sleep apnea benefit from avoiding or limiting alcohol intake and smoking. They should avoid sleeping pills and other sedating medications unless directed to use them by a knowledgeable care provider. Depending on the dose consumed, alcohol, hypnotics, and sedatives may make a patient's upper airway more likely to collapse during sleep and interfere with the arousals that terminate these airway collapses. Certain medications, such as trazodone and theophylline, may slightly reduce the severity of apneas in some patients. 

Nasal continuous positive airway pressure (CPAP) is the most effective treatment for obstructive sleep apnea. Sufficient air pressure is introduced into the nose to inflate the upper airway enough to prevent collapse during sleep. The air pressure is generated by a flow generator , which is attached to a tube that connects to an air tight nasal or nasal/oral mask or a tube with branches that insert into the outer parts of the nostrils. This tube is similar to the one commonly used for applying nasal oxygen through the nostrils.

Dental appliances that fit onto the teeth and hold the jaw and tongue forward widen the airway and can be helpful for mild sleep apnea. 

Dentists with appropriate expertise can fit these devices

A variety of surgical procedures have been used to treat obstructive sleep apnea. When large tonsils and adenoids are an important contributing factor tonsillectomy and adenoidectomy can be helpful.

Gastric bypass procedures that cause major weight loss can cure sleep apnea in about 30-50 percent, depending on the exact criteria used. The most effective surgical treatment is maxillomandibular advancement, where the jaw bones are moved forward.

Provent is a nasal peel-stick valve that is effective in a minority of patients, and is FDA approved. Winx is a treatment that used oral suction to move the tongue forward and is FDA approved for sleep apnea treatment. Hypoglossal nerve stimulation (stimulating the nerve to the tongue) has also been recently approved by the FDA for selected patients.

Weight loss can be helpful for overweight patients. Unfortunately, inducing enduring weight loss is often difficult. Restriction of calories and an increase in exercise are helpful, but may be difficult to maintain.

The treatment of central and complex apnea is more difficult and often requires positive airway pressure (adaptive ventilation is FDA approved), measures to stabilize oxygen and carbon dioxide, drugs that can stabilize breathing control (acetazolamide and topiramate) and sometimes sedatives to reduce arousals from sleep.

The center also treats patients with respiratory failure, which is often worse or present only during sleep. Such patients may have lung disease, or muscle / nervous system disorders. Special monitoring of carbon dioxide is possible in the sleep laboratory and at home, as well as the use of advanced treatment devices including ventilators.