What Causes Sleep Apnea?
When you’re awake, throat muscles help keep your airway stiff and open so air can flow into your lungs. When you sleep, these muscles are more relaxed. Normally, the relaxed throat muscles don’t stop your airway from staying open to allow air into your lungs.
But if you have obstructive sleep apnea, your airways can be blocked or narrowed during sleep because:
- Your throat muscles and tongue relax more than normal.
- Your tongue and tonsils (tissue masses in the back of your mouth) are large compared to the opening into your windpipe.
- You’re overweight. The extra soft fat tissue can thicken the wall of the windpipe. This causes the inside opening to narrow and makes it harder to keep open.
- The shape of your head and neck (bony structure) may cause a smaller airway size in the mouth and throat area.
- The aging process limits the ability of brain signals to keep your throat muscles stiff during sleep. This makes it more likely that the airway will narrow or collapse.
Not enough air flows into your lungs when your airways are fully or partly blocked during sleep. This can cause loud snoring and a drop in your blood oxygen levels.
When the oxygen drops to dangerous levels, it triggers your brain to disturb your sleep. This helps tighten the upper airway muscles and open your windpipe. Normal breaths then start again, often with a loud snort or choking sound.
The frequent drops in oxygen levels and reduced sleep quality trigger the release of stress hormones. These compounds raise your heart rate and increase your risk for high blood pressure, heart attack, stroke, and irregular heartbeats. The hormones also raise the risk for or worsen heart failure.
Untreated sleep apnea also can lead to changes in how your body uses energy. These changes increase your risk for obesity and diabetes.
Who Is At Risk for Sleep Apnea?
It’s estimated that more than 12 million American adults have obstructive sleep apnea. More than half of the people who have this condition are overweight.
Sleep apnea is more common in men. One out of 25 middle-aged men and 1 out of 50 middle-aged women have sleep apnea.
Sleep apnea becomes more common as you get older. At least 1 out of 10 people over the age of 65 has sleep apnea. Women are much more likely to develop sleep apnea after menopause.
African Americans, Hispanics, and Pacific Islanders are more likely to develop sleep apnea than Caucasians.
If someone in your family has sleep apnea, you’re more likely to develop it.
People who have small airways in their noses, throats, or mouths also are more likely to have sleep apnea. Smaller airways may be due to the shape of these structures or allergies or other medical conditions that cause congestion in these areas.
Small children often have enlarged tonsil tissues in the throat. This can make them prone to developing sleep apnea.
Other risk factors for sleep apnea include smoking, high blood pressure, and risk factors for stroke or heart failure.
Signs and Symptoms of Sleep Apnea?
One of the most common signs of obstructive sleep apnea is loud and chronic (ongoing) snoring. Pauses may occur in the snoring. Choking or gasping may follow the pauses.
The snoring usually is loudest when you sleep on your back; it may be less noisy when you turn on your side. Snoring may not happen every night. Over time, the snoring may happen more often and get louder.
You’re asleep when the snoring or gasping occurs. You will likely not know that you’re having problems breathing or be able to judge how severe the problem is. Your family members or bed partner will often notice these problems before you do.
Not everyone who snores has sleep apnea, but not everyone who has sleep apnea snores, either.
Another common sign of sleep apnea is fighting sleepiness during the day, at work, or while driving. You may find yourself rapidly falling asleep during the quiet moments of the day when you’re not active.
Other Signs and Symptoms
Others signs and symptoms of sleep apnea may include:
- Morning headaches
- Memory or learning problems and not being able to concentrate
- Feeling irritable, depressed, or having mood swings or personality changes
- Urination at night
- A dry throat when you wake up
In children, sleep apnea can cause hyperactivity, poor school performance, and aggressiveness. Children who have sleep apnea also may have unusual sleeping positions, bedwetting, and may breathe through their mouths instead of their noses during the day.
