What Causes Sleep Apnea?
With obstructive sleep apnea, breathing frequently stops during sleep for seconds at a time before starting again. Diagnosing the underlying cause of sleep apnea is often an important step in resolving symptoms and preventing potentially serious complications. Let’s take a look at some of the various medical issues that may lead to a sleep apnea diagnosis.
In adults, the most common cause of sleep apnea is obesity, especially excess weight around the neck area. During sleep, tongue and throat muscles relax, which may allow this additional weight to block the airway, causing a temporary pause in breathing. More than half of adults with obstructive sleep apnea are overweight or obese. Risk of sleep apnea increases by 14 percent with every increase of body mass index, or BMI (for example, from 29 to 30), and a 10 percent weight gain makes an individual six times more likely to develop sleep apnea. In addition to BMI over 25, men with a neck circumference above 17 inches and women with a neck circumference above 15 inches are at a much higher risk for sleep apnea than individuals at a normal weight.
Birth Defects and Anatomical Features
In children, enlarged tonsils can lead to obstructive sleep apnea, as can dental issues such as an overbite. In most cases, the apnea resolves when tonsils and adenoids are removed or bite problems corrected with orthodontia.
Down syndrome and Pierre-Robin syndrome are the genetic conditions most commonly associated with sleep apnea. Down syndrome sometimes results in enlargement of the tongue, adenoids and tonsils along with decreased muscle tone in the upper airway, issues that combine to obstruct the airway during sleep. Those with Pierre-Robin syndrome are characterized by a small lower jaw and a tongue that tends to fall to the back of the throat during sleep, both of which can contribute to obstructive sleep apnea.
Absent of any medical issues, some individuals have naturally rounded heads, narrow throats or thick necks that make sleep apnea more likely. These abnormalities may be inherited since sleep apnea is up to 40 percent more likely among those who have a family member with the condition.
Those with certain medical conditions are more likely to develop sleep apnea. These conditions include hypothyroidism, excessive production of growth hormone (acromegaly), and allergies, deviated septum or other causes of congestion in the upper airways.
Smoking, alcohol abuse and the use of sedative medications or sleeping pills are all associated with the development of obstructive sleep apnea.
The risk for developing sleep apnea increases with age. This condition occurs in 4 to 9 percent of middle-aged adults and in more than 10 percent of adults older than age 65. That’s because aging leads to difficulty keeping throat muscles during sleep, causing breathing to become obstructed.
Men younger than age 65 are four times more likely to develop sleep apnea than women in the same age group, though this gap closes after women reach menopause. However, pregnant women and those undergoing menopause are at higher risk for this condition than are men of the same age.
Central sleep apnea is a less common form of this condition that occurs when the brain fails to send breathing signals to the lungs during sleep.
Left untreated, sleep apnea can lead to serious complications like high blood pressure, stroke, heart attack, diabetes, gastroesophageal reflux disease, nocturnal angina, heart failure, hypothyroidism and abnormal heart rhythm. And because this condition leads to excessive sleepiness during the day, it can result in depression, difficulty with work and relationships and even motor vehicle accidents. Talk with your doctor if you’re experiencing symptoms associated with sleep apnea to see f you may qualify for a home sleep test.