A sleep disorder (somnipathy) is a medical disorder of the sleep patterns of a person. Some sleep disorders are serious enough to interfere with normal physical, mental and emotional functioning. A test commonly ordered for some sleep disorders is the polysomnogram.
The Major Sleep Disorders are:
Insomnia is a symptom of a sleeping disorder characterized by persistent difficulty falling asleep or staying asleep despite the opportunity. Insomnia is a symptom, not a stand-alone diagnosis or a disease. By definition, insomnia is “difficulty initiating or maintaining sleep or both” and it may be due to inadequate quality or quantity of sleep. It is typically followed by functional impairment while awake. Both organic and non-organic insomnia constitute a sleep disorder.
Narcolepsy is a chronic sleep disorder characterized by overwhelming drowsiness and sudden attacks of sleep. The condition is most characterized by excessive daytime sleepiness (EDS), in which a person experiences extreme tiredness and possibly falls asleep during inappropriate times, such as at work or school. A narcoleptic will most probably experience disturbed nocturnal sleep, which is often confused with insomnia, and disorder of rapid eye movement sleep.
Cataplexy, a sudden muscular weakness brought on by strong emotions, is a medical condition which may also affect narcoleptics. Often manifesting as muscular weaknesses ranging from a barely perceptible slackening of the facial muscles to the dropping of the jaw or head, weakness at the knees, or a total collapse. Usually only speech is slurred, vision is impaired (double vision, inability to focus), but hearing and awareness remain normal. In some rare cases, an individual’s body becomes paralyzed and muscles will become stiff.
Restless legs syndrome is a condition that is characterized by an irresistible urge to move one’s body to stop uncomfortable or odd sensations. It most commonly affects the legs, but can also affect the arms or torso. Moving the affected body part modulates the sensations, providing temporary relief. RLS causes a sensation in the legs or arms that can most closely be compared to a burning, itching, or tickling sensation in the muscles.
Sleepwalking or somnambulism or noctambulism is a parasomnia or sleep disorder where the sufferer engages in activities that are normally associated with wakefulness while he or she is asleep or in a sleep-like state. Sleepwalking is usually defined by or involves the person affected apparently shifting from his or her prior sleeping position and moving around and performing normal actions as if awake (cleaning, walking and other activities). It is inexact to assume that somnambulists are unconscious during their nocturnal sleepwalking episodes. They are simply not conscious of their actions on a level where memory of the sleepwalking episode can be recalled, and because of this, unless the sleepwalker is awakened or aroused by someone else, this sleep disorder can go unnoticed. Sleepwalking is more commonly experienced in people with high levels of stress, anxiety or psychological factors and in people with genetic factors or sometimes a combination of both.