Causes

Obstructive sleep apnea occurs when the muscles in the back of your throat relax too much to allow normal breathing. These muscles support structures including the back of the roof of your mouth (soft palate), the triangular piece of tissue hanging from the soft palate (uvula), the tonsils and the tongue.

When the muscles relax, your airway narrows or closes as you breathe in, hampering your breathing for 10 seconds or longer. This can lower the level of oxygen in your blood and cause a buildup of carbon dioxide.

Your brain senses this impaired breathing and briefly rouses you from sleep so that you can reopen your airway. This awakening is usually so brief that you don't remember it.

You can awaken with shortness of breath that corrects itself quickly, within one or two deep breaths. You might make a snorting, choking or gasping sound.

This pattern can repeat itself five to 30 times or more each hour, all night long. These disruptions impair your ability to reach the deep, restful phases of sleep, and you'll probably feel sleepy during your waking hours.

People with obstructive sleep apnea might not be aware of their interrupted sleep. Many people with this type of sleep apnea don't realize they haven't slept well all night.