Sleepiness and sleep disorders. Causes and consequences.

Sleepiness and sleep disorders are prevalent in our society. Symptoms of sleepiness and complaints referable to sleep disorders have generally--and incorrectly--been discounted as being of minor importance and are often thought to be manifestations of psychological problems or character defects. It is now apparent that the cost to the American public--both to individuals and the larger society--is substantial. Sleep medicine has become established as an independent field, and knowledge of sleep, sleepiness, and sleep disorders has grown dramatically. This knowledge, when applied to individuals, will enhance the lives of patients with sleep disorders, and when applied to society as a whole, will have important socioeconomic implications.