The International RLS Study Group have set out criteria on which a diagnosis of RLS may be made. These are:

  • Highly unpleasant sensations in the legs and sometimes arms and other parts of the body that are described as creepy, crawly, shock-like, itchy or even painful.
  • The sensations cause an irresistible urge to move.
  • Movement provides temporary relief so long as the movement continues.
  • The symptoms occur in situations of rest and peak during the evening and at night.
  • The occurence of the above features are not solely accounted for as symptoms primary to another medical or behavioural condition e.g. myalgia, arthritis, habitual foot tapping, leg cramps, positional discomfort.

RLS occurs in 7-10 % of the adult population worldwide. One third of these patients need pharmaceutical treatment to live a normal life.

There are two forms of RLS:

  • Primary or idiopathic - RLS is familial in one-third of cases. The cause in the remaining 70% is unknown.
  • Secondary or symptomatic - RLS is the result of a number of conditions, among which iron deficiency, end-stage renal failure and neuropathy are the most important. 25 – 30% of blood donors have been found to have RLS. Some 25% of pregnant women experience symptoms, mainly during the last trimester - the last three months of pregnancy.

The exact cause of RLS is not known. Many recent studies have shown that there is impaired dopaminergic neurotransmission. There is no dopaminergic hypofunction. New data point towards a hyper dopaminergic neuronal extracellular situation. Iron plays an important role in the optimal function of the dopaminergic system.

RLS is often unrecognized or misdiagnosed. Patients usually delay seeking medical help for many years. When they finally do, an accurate diagnosis often is not made until many years thereafter. A large study completed in 2004 showed that only 8% of the many thousands of patients who took part received an RLS diagnosis.

Many people with RLS have relatively mild symptoms which may be alleviated by changes in lifestyle, such as avoiding alcohol and nicotine. But there is a substantial group of patients with symptoms so severe that treatment is called for. The chronic lack of sleep that accompanies RLS often significantly impacts on daytime functioning, and therefore quality of life.

RLS is an important disease because it is common, because it causes significant distress to the sufferers, and because it may be the presenting symptom of another serious underlying disease.