In most cases, sleep debt has a natural way of resolving itself. The homeostatic relationship between wakefulness and sleep discourages normal people from becoming dangerously sleep deprived. The body reacts to a lack of sleep by having daytime drowsiness such that an intense desire to sleep induces the person to either go to sleep early or sleep in late. Six to eight hours per day is the average amount of sleep a person needs. As a population, we sleep about 1 to 1.5 hours less than we did 100 years ago.
Sleep requirements vary from person to person-some people are naturally short or long sleepers.
Thomas Edison, Martha Stewart, and Jay Leno have remarked that they sleep less than five hours a night. In contrast, Albert Einstein and Calvin Coolidge claimed they needed ten or more hours per night. Other well-known people such as Ronald Reagan and Winston Churchill took naps throughout the day. Some experts suggest that the best way to determine personal sleep requirements is by waking up without an alarm clock. The amount of time spent sleeping would be the personal requirement.