Restless legs syndrome (RLS) is a common sleep disorder that causes significant sleep disturbance and negatively affects quality of life. It is characterized by an overwhelming urge to move the legs due to uncomfortable sensations. The diagnosis is based on clinical features, and several disorders may mimic RLS. RLS is more common in individuals with iron deficiency anemia, and iron replacement can resolve or reduce symptoms. Dopamine agonists are the initial therapy for RLS, with low doses taken in the evening or 2 hours before bed. However, augmentation, a worsening of symptoms, is common with dopamine agents, especially levodopa. Opiates and antiepileptics are beneficial for RLS, particularly in patients with pain. Newer anticonvulsants may provide additional treatment options but have not been fully evaluated. Intravenous iron may relieve RLS symptoms, but dosing and safety issues remain unclear. RLS is often associated with periodic limb movements during sleep (PLMS), but PLMS are not required for diagnosis. PLMS can result from sleep disordered breathing or neuropathic disorders. RLS has a familial component, especially in those with early onset. Genetic studies suggest an autosomal dominant mode of inheritance with loci on chromosomes 14q and 12q. Prevalence varies by country, with rates as low as 0.1% in Singapore and up to 15% in French-Canadians. Iron deficiency is a key factor in RLS, with a serum ferritin level below 50 μg/L indicating increased severity. Iron replacement is effective for RLS patients with known iron deficiency. The initial evaluation for RLS should include serum iron indices, with ferritin and iron saturation levels more reflective of true iron status. Polysomnography is reserved for cases with suspected sleep disorders. Current therapy focuses on dopamine agents, which are effective in reducing RLS symptoms and improving sleep. However, augmentation is a notable problem, especially with levodopa. Patients with worsening symptoms should be switched to anticonvulsants or opiates. Benzodiazepines were used in the past but are less effective now.Restless legs syndrome (RLS) is a common sleep disorder that causes significant sleep disturbance and negatively affects quality of life. It is characterized by an overwhelming urge to move the legs due to uncomfortable sensations. The diagnosis is based on clinical features, and several disorders may mimic RLS. RLS is more common in individuals with iron deficiency anemia, and iron replacement can resolve or reduce symptoms. Dopamine agonists are the initial therapy for RLS, with low doses taken in the evening or 2 hours before bed. However, augmentation, a worsening of symptoms, is common with dopamine agents, especially levodopa. Opiates and antiepileptics are beneficial for RLS, particularly in patients with pain. Newer anticonvulsants may provide additional treatment options but have not been fully evaluated. Intravenous iron may relieve RLS symptoms, but dosing and safety issues remain unclear. RLS is often associated with periodic limb movements during sleep (PLMS), but PLMS are not required for diagnosis. PLMS can result from sleep disordered breathing or neuropathic disorders. RLS has a familial component, especially in those with early onset. Genetic studies suggest an autosomal dominant mode of inheritance with loci on chromosomes 14q and 12q. Prevalence varies by country, with rates as low as 0.1% in Singapore and up to 15% in French-Canadians. Iron deficiency is a key factor in RLS, with a serum ferritin level below 50 μg/L indicating increased severity. Iron replacement is effective for RLS patients with known iron deficiency. The initial evaluation for RLS should include serum iron indices, with ferritin and iron saturation levels more reflective of true iron status. Polysomnography is reserved for cases with suspected sleep disorders. Current therapy focuses on dopamine agents, which are effective in reducing RLS symptoms and improving sleep. However, augmentation is a notable problem, especially with levodopa. Patients with worsening symptoms should be switched to anticonvulsants or opiates. Benzodiazepines were used in the past but are less effective now.