-----Central sleep apnea, which is less common, occurs when the brain fails to send the appropriate signals to the breathing muscles to initiate respirations.
-----Obstructive sleep apnea is far more common and occurs when air cannot flow into or out of the person's nose or mouth although efforts to breathe continue. In a given night, the number of involuntary breathing pauses or "apneic events" may be as high as 20 to 30 or more per hour. These breathing pauses are almost always accompanied by snoring between apnea episodes, although not everyone who snores has this condition. Sleep apnea can also be characterized by choking sensations. The frequent interruptions of deep, restorative sleep often lead to early morning headaches and excessive daytime sleepiness. Early recognition and treatment of sleep apnea is important because it may be associated with irregular heartbeat, high blood pressure, heart attack, and stroke.
How Is Normal Breathing Restored During Sleep?
What Are The Effects Of Sleep Apnea?