Sleep apnea is a potentially serious sleep disorder in which breathing repeatedly stops and starts. If you snore loudly and feel tired even after a full night's sleep, you might have sleep apnea. If you think you might have sleep apnea, see your doctor. Treatment can ease your symptoms and might help prevent heart problems and other complications. Your doctor may make an evaluation based on your signs and symptoms and a sleep history, which you can provide with help from someone who shares your bed or your household, if possible. You're likely to be referred to a sleep disorder center. There, a sleep specialist can help you determine your need for further evaluation.