When you sleep, all of the muscles in your body become more relaxed. This includes the muscles that help keep your throat open so air can flow into your lungs.
Normally, your throat remains open enough during sleep to let air pass by. Some people have a narrow throat. When the muscles in their upper throat relax during sleep, the tissues close in and block the airway. This stop in breathing is called apnea.
Loud snoring is a telltale symptom of sleep apnea. Snoring is caused by air squeezing through the narrowed or blocked airway. Not everyone who snores has sleep apnea though.
Other factors also may increase your risk:
A lower jaw that is short compared to your upper jaw
Certain shapes of the roof of your mouth (palate) or airway that cause it to collapse more easily
Large neck or collar size (17 inches or more in men and 16 inches or more in women)
Large tongue, which may fall back and block the airway
Large tonsils and adenoids that can block the airway
Sleeping on your back can also cause your airway to become blocked or narrowed.
Central sleep apnea is another sleep disorder during which breathing can stop. It occurs when the brain temporarily stops sending signals to the muscles that control breathing.
If you have obstructive sleep apnea, you usually begin snoring heavily soon after falling asleep.
The snoring often becomes very loud.
Snoring is interrupted by a long silent period while your breathing stops.
The silence is followed by a loud snort and gasp, as you attempt to breathe.
This pattern repeats throughout the night.
Most people with obstructive sleep apnea do not know their breathing starts and stops during the night. Usually, a sleep partner or other family members hear the loud snoring, gasping, and snorting. Snoring can be loud enough to hear through walls.
People with sleep apnea may:
Wake up unrefreshed in the morning
Feel sleepy or drowsy throughout the day
Act grumpy, impatient, or irritable
Fall asleep while working, reading, or watching TV
Feel sleepy while driving or even fall asleep while driving
You or your family notice symptoms of obstructive sleep apnea
Symptoms do not improve with treatment, or new symptoms develop
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Andrew Schriber, MD, FCCP, Specialist in Pulmonary, Critical Care, and Sleep Medicine, Virtua Memorial Hospital, Mount Holly, NJ. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.