Nowadays, more and more people are to some extent sleep-deprived  because of some increasing demands at work, family responsibilities, social activities, etc. Thus, sleep disorders are largely to blame. While the amount of sleep required depends on the individual, most people function best with about eight hours of sleep a night. Adequate sleep makes people feel refreshed and alert. The consequences of sleep deprivation can be devastating. It can adversely affect cognitive function, potentially leading to attention difficulties and traffic collisions. It is well documented that sleep loss can also negatively affect mood. Sleep deprivation has been associated with medical consequences such as weight gain, aggravation of diabetes, immune-system problems, high blood pressure and cardiovascular disease.