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 relax, which narrows your throat.
Normally, this narrowing doesn’t prevent air from flowing into and out of your lungs. But if you have sleep apnea, your airway can become partially or fully blocked 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 with the opening into your windpipe.
- You're overweight. The extra soft fat tissue can thicken the wall of the windpipe. This narrows the inside of the windpipe, which 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 your brain signals' ability to keep your throat muscles stiff during sleep. Thus, your airway is more likely to narrow or collapse.
Not enough air flows into your lungs if your airway is partially or fully blocked during sleep. As a result, loud snoring and a drop in your blood oxygen level can occur.
If the oxygen drops to a dangerous level, it triggers your brain to disturb your sleep. This helps tighten the upper airway muscles and open your windpipe. Normal breathing then starts again, often with a loud snort or choking sound.
Frequent drops in your blood oxygen level and reduced sleep quality can trigger the release of stress hormones. These hormones raise your heart rate and increase your risk for high blood pressure, heart attack, stroke, and arrhythmias (irregular heartbeats). The hormones also can raise your risk for, or worsen, heart failure.
Sleep Apnea Research: The HeartBeat Study06/07/2012
In this video—presented by the National Heart, Lung, and Blood Institute, part of the National Institutes of Health—Dr. Susan Redline of Harvard Medical School/Brigham and Women's Hospital discusses her ongoing sleep apnea research. Sleep apnea is a common disorder that can raise your risk for high blood pressure, heart attack, stroke, arrhythmias (irregular heartbeats), heart failure, obesity, and diabetes.
One of Dr. Redline's projects, the HeartBEAT Study, is comparing treatments for sleep apnea to see whether they lower the risk of heart disease. The results of this research, which is funded by the American Recovery and Reinvestment Act of 2009, may help reduce deaths from heart attacks and strokes.
Living With and Managing Sleep Apnea05/18/2011
This video—presented by the National Heart, Lung, and Blood Institute, part of the National Institutes of Health—shows how Jim, the father of two young girls, has coped with having sleep apnea. Symptoms such as waking up tired and falling asleep while driving long distances made Jim concerned about his health. While Jim was sleeping, his wife noticed snoring and long periods of silence followed by gasps.
Wanting a better quality of life, Jim sought the advice of his doctor, who recommended a sleep study. As a result of the sleep study, Jim was diagnosed with severe obstructive sleep apnea and prescribed treatment with a CPAP machine. CPAP provides mild air pressure to keep the airways open during sleep.
Jim explains that adjusting to CPAP treatment was hard at first, and his inability to stick with the treatment led to more symptoms. However, after using the CPAP machine regularly, Jim feels better and has more energy to do activities with his children.
For more information about living with and managing sleep apnea, go to the Health Topics Sleep Apnea article.