Sleep apnea is a serious, potentially life-threatening sleep disorder that occurs when an individual stops breathing for short periods of time during sleep. Because sleep apnea causes individuals to wake up frequently throughout the night, patients often are drowsy during the day.
There are two main types of sleep apnea: obstructive and central. When a patient has both types, they’re said to have complex sleep apnea.
Obstructive sleep apnea
The most common form of sleep apnea, obstructive sleep apnea occurs when your breathing is interrupted during sleep for longer than 10 seconds. When your breathing is reduced and you're not taking in enough oxygen, these episodes are called hypopneas. They're called apneas if your breathing stops completely.
Obstructive sleep apnea happens when the muscles in your throat relax and block your airway enough to interrupt breathing. The brain senses this inability to breathe and causes the individual to wake up and start breathing again. This process may occur 20 to 30 times or more each hour during sleep. Most patients do not even realize this happens.
Anyone at any age can have obstructive sleep apnea, but it's most common in middle-aged and older adults. About 2-3 percent of children have obstructive sleep apnea. It is also twice as likely to occur in men as women. Obese individuals have an increased risk for experiencing obstructive sleep apnea because they have excess fat in their upper airway.
For one thing, apnea raises blood pressure. “When you stop breathing, your body produces a burst of adrenaline as you gasp for air,” says pulmonologist Richard Strobel, MD, with Lehigh Valley Health Network’s Sleep Disorders Center. “This causes sudden spikes in blood pressure that damage your heart.”
Hypertension (high blood pressure) raises the risk for atrial fibrillation, a condition that causes the heart to beat irregularly. When your heart doesn’t beat properly, blood can pool or clot and cause a heart attack or stroke.
Not getting quality sleep can have other deadly consequences. “There is strong evidence linking sleep apnea and car accidents,” says family medicine doctor Jeffrey Brown, DO, with Lehigh Valley Health Network.
Central sleep apnea
Central sleep apnea occurs when the brain does not send proper signals to the muscles that control breathing during sleep. People with central sleep apnea are more likely to remember waking up in the middle of sleep than patients with obstructive sleep apnea.
Central sleep apnea may develop at any age, and it affects males and females equally. Central sleep apnea may be caused by neurological issues and/or opiod medication use.
Complex sleep apnea
It is possible to have a combination of both types of sleep apnea, which is called complex sleep apnea. Some evidence suggests that 15 percent of patients with sleep apnea have complex sleep apnea.
Causes of sleep apnea
Sleep apnea 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.