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. |