The sleep apnea syndrome is defined as

Sleep apnea is a potentially serious sleep disorder in which breathing repeatedly stops and stas. If you snore loudly and feel tired even after a full night's sleep, you might have sleep apnea. The main types of sleep apnea are: Obstructive sleep apnea, the more common form that occurs when throat muscles relax Central sleep apnea, which occurs when your brain doesn't send proper signals to the muscles that control breathing Complex sleep apnea syndrome, also known as treatment-emergent central sleep apnea, which occurs when someone has both obstructive sleep apnea and central sleep apnea