Have you been diagnosed with obstructive sleep apnea? If so, you might be relieved to know that it is a fairly common sleep disorder. Obstructive sleep apnea occurs when the muscles in the throat relax during sleep. The relaxed muscles cause the airway to become narrowed or obstructed. When the airway is blocked, it prevents normal breathing during sleep. Symptoms of obstructive sleep apnea usually include loud snoring, gasping for air, and abrupt awakenings.