Sleep apnea is a common disorder that will cause a person to wake up 100-300 times per night due to blockage of the airway. The soft tissue in the back of the throat collapses, blocking the airway. Normal sleep will resume, but usually after a person exerts a loud snort, or choking sound. This disorder is one of the leading causes for daytime sleepiness. When airways are cut off or even constricted, a person will fall out of a deep sleep and into a lighter one. The deeper a sleep, the better quality it is for the person.