Sleep Disorders are medical disorders of the sleep patterns of a person or animal. It is common but not easy to be diagnosed as a single condition. For example, Insomnia, a kind of sleep disorder, is not a disease, as there is no single definition that can apply to all the conditions reported by people. Some sleep disorders are severe enough to interfere with normal physical, mental, social, and emotional functions.
According to recent surveys, nearly 30% of adults have sleep disorders, with an average sleep time of less than 6 hours per night, and 70% of teenagers have an average sleep time of less than 8 hours. Compared with 20 years ago, infants and toddlers wake up much more every night and also sleep much less.