Medical Author: Melissa Stoppler, M.D.
Medical Editor: Barbara K. Hecht, Ph.D.
Restless leg syndrome (RLS), also known as nocturnal myoclonus, is a type of sleep disorder characterized by uncomfortable sensations in the legs and an uncontrollable desire to move the legs. These abnormal sensations usually occur in the lower legs shortly after going to bed. During the early stages of sleep, these episodes of leg movement often last up to an hour.
The abnormal sensations of RLS are quite variable. They have been described as a crawling, creeping, pulling, drawing, tingling, pins and needles, or prickly discomfort. They are not cramping in character.
Sometimes these sensations occur in the feet, thighs or even arms. Although RLS is considered to be a sleep disorder, some people also experience these sensations during the day, particularly when lying down.
The most important feature of RLS is an overwhelming need to move the legs. Moving the legs provides temporary relief but the abnormal sensations start all over again and the cycle repeats itself.
While the cause of RLS is unknown, it does tend to occur in association with a number of chronic conditions including iron deficiency anemia, obesity, diabetes, diseases of the peripheral nerves, and kidney failure. However, many persons with RLS will not have any identifiable predisposing disease or condition.
RLS is most common in middle-aged and older adults and is worse during periods of psychological stress. The use of some prescription drugs -- for example, the antidepressant Elavil (amitriptyline) and stomach acid blockers such as Zantac or Tagamet -- has been associated with RLS. Caffeine, alcohol, and tobacco use may also trigger RLS.
There is no known cure for RLS. Treatment is directed toward any condition underlying RLS. Avoidance of caffeine and alcohol can sometimes help.
Your doctor may prescribe medication, if your RLS is severe. A number of different types of drugs, including opioids, tranquilizers, anti-Parkinson drugs, and anticonvulsants, have been found effective. Stress management and relaxation training have also been found to prevent episodes of RLS.
RLS is thought to be more common in women than men. It can cause insomnia with daytime fatigue and associated discomfort. As the years go on, the symptoms of RLS may occur more frequently and for longer periods of time.