Obstructive sleep apnea is a potentially serious sleep disorder. It causes breathing to repeatedly stop and start during sleep.There are several types of sleep apnea, but the most common is obstructive sleep apnea. This type of apnea occurs when your throat muscles intermittently relax and block your airway during sleep. A noticeable sign of obstructive sleep apnea is snoring. Treatments for obstructive sleep apnea are available. One treatment involves using a device that keep your airway open while you sleep. Another option is a mouthpiece to thrust your jaw forward during sleep. In more severe cases, surgery may be an option too