Sleep Apnea Symptoms and Causes
About Sleep Apnea
Sleep apnea is a serious, potentially life-threatening condition that is far more common than generally understood. Sleep apnea occurs in all age groups and both genders. It is more common in men, although it may be under-diagnosed in women and young African-Americans. It is estimated that as many as 18 million Americans have sleep apnea.
Early recognition and treatment of sleep apnea is important, as it may be associated with the following:
- Irregular heartbeat
- High blood pressure
- Heart attack
Sleep apnea is characterized by a number of involuntary breathing pauses or "apneic events" during a single night's sleep - may be as many as 20 to 30 or more events per hour. These events are almost always accompanied by snoring between apnea episodes (although not everyone who snores has sleep apnea). Sleep apnea may also be characterized by choking sensations. The frequent interruptions of deep, restorative sleep often lead to early morning headaches and excessive daytime sleepiness.
During the apneic event, the person is unable to breathe in oxygen and to exhale carbon dioxide, resulting in low levels of oxygen and increased levels of carbon dioxide in the blood. The reduction in oxygen and increase in carbon dioxide alert the brain to resume breathing and cause an arousal. With each arousal, a signal is sent from the brain to the upper airway muscles to open the airway; breathing is resumed, often with a loud snort or gasp. Frequent arousals, although necessary for breathing to restart, prevent a person from getting enough restorative, deep sleep.
Sleep Apnea Symptoms
Sleep apnea is a breathing disorder characterized by brief interruptions of breathing during sleep. There are two types of sleep apnea:
- Central — occurs when the brain fails to send the appropriate signals to the muscles to initiate breathing. Central sleep apnea is less common than obstructive sleep apnea.
- Obstructive — occurs when air cannot flow into or out of the person's nose or mouth although efforts to breathe continue.
Sleep Apnea Causes
Certain mechanical and structural problems in the airway cause the interruptions in breathing during sleep. Apnea occurs:
- When the throat muscles and tongue relax during sleep and partially block the opening of the airway.
- When the muscles of the soft palate at the base of the tongue and the uvula relax and sag, the airway becomes blocked, making breathing labored and noisy and even stopping it altogether.
- In obese people when an excess amount of tissue in the airway causes it to be narrowed.
- With a narrowed airway, the person continues his/her efforts to breathe, but air cannot easily flow into or out of the nose or mouth.
Sleep apnea also seems to run in some families, suggesting a possible genetic basis. People most likely to have or develop sleep apnea include those who:
- Snore loudly.
- Are overweight.
- Have high blood pressure.
- Have some physical abnormality in the nose, throat, or other parts of the upper airway.
- Use of alcohol and sleeping pills increases the frequency and duration of breathing pauses in people with sleep apnea.