Have you been told that you frequently snore at night, or do you often wake up in the morning still exhausted, even though you slept all night? If so, you may be experiencing symptoms of a common condition known as sleep apnea. Sleep apnea is a serious condition in which a person stops breathing multiple times throughout the night. It occurs when the muscles in the back of the throat relax during sleep, blocking the airway and restricting your breathing. When you stop breathing, your brain is alert, causing you to wake. The waking periods are so short that you are unaware that you are not sleeping.