The amount of sleep a person needs depends on many factors, including age. For example, in general Infants require about 16 hours a day,
Teenagers need about 9 hours on average, most adults need 7 to 8 hours a night for the best amount of sleep, although some people may need as few as 5 hours or as many as 10 hours of sleep each day.
Women in the first 3 months of pregnancy often need several more hours of sleep than usual; however, experts say that if you feel drowsy during the day, even during boring activities, you haven’t had enough sleep.
The amount of sleep a person needs also increases if he or she has been deprived of sleep in previous days. Getting too little sleep creates a ‘sleep debt’, which is much like being overdrawn at a bank. Eventually, your body will demand that the debt be repaid.
We don’t seem to adapt to getting less sleep than we need, while we may get used to a sleep-depriving schedule, our judgment, reaction time, and other functions are still impaired. Too little sleep may cause Memory problems, depression and a weakening of your immune system, increasing your chance of becoming ill.