Sleep Disorders

Sleep disorders are a collection of syndromes characterized by disorder in the patient's amount of sleep, quality or timing of sleep, or in behaviors or physiological conditions connected with sleep. There are about seventy different sleep disorders. To meet the criteria for the diagnosis of sleep disorder, the condition must be a persistent problem, cause the patient significant emotional distress, and hinder with his or her social or occupational functioning. The standard length of nighttime sleep varies amongst people. Most people sleep between 7 and 9 hours a night. This population average appears to be constant throughout the world. In temperate climates, however, people often observe that sleep time varies with the seasons. It is not strange for people in North America and Europe to sleep about 40 minutes longer per night during the winter.