I. What is restless legs syndrome? Restless legs syndrome (RLS), also known as Willis-Ekbom disease, is a sleep-related movement disorder. If you have RLS, you usually have a strong desire to kick your legs or move them. This can cause you to wake up from sleep or have difficulty falling asleep, which can interfere with work, school and life during the day. Most RLS is idiopathic, and most runs in families. In a few cases, RLS is associated with other health problems. For example, iron deficiency anemia, renal failure (uremia), diabetes, and multiple sclerosis. In addition, pregnant women are also at high risk for RLS. Second, what are the typical symptoms of RLS? Patients with RLS have an unusually uncomfortable sensation in their legs when they are at rest. They describe this sensation as crawling, writhing, pulling, and itching. This sensation occurs deep in the lower extremities rather than on the surface of the skin, usually below the knee joint. These symptoms are mildest in the morning and gradually worsen as time passes, and are most pronounced and severe at night. The symptoms may be partially or completely relieved after kicking and walking and other activities of the legs. Some patients have been found to have involuntary leg tremors when they are asleep (periodic limb movement disorder). Third, what tests should be done for the diagnosis of RLS? 1. The diagnosis of RLS can be made by the doctor based on typical symptom characteristics, effective dopamine-based medication, and a family history, and no special tests are usually needed. If tests are needed, the doctor’s purpose may be: 2. Polysomnography, which requires staying in the sleep lab all night with the body hooked up to multiple leads. It is used to assess the presence and severity of periodic limb movements, objective sleep quality indicators (e.g. sleep efficiency, sleep structure, number of awakenings, duration of awakenings, etc.). 3. Other tests, such as ferritin level, renal function, blood glucose, nerve conduction velocity, etc., are used to assess whether there are risk factors for RLS or aggravating factors that can be intervened. IV. What are the special manifestations of RLS in children? Children are often unable to describe the symptoms of RLS correctly due to differences in language expression. Some children with RLS are misdiagnosed as “growing pains”. Children can describe their symptoms in their own words. Figures 1 and 2 show two children with RLS expressing their RLS symptoms by drawing pictures.