Patients with restless legs syndrome often have difficulty describing their symptoms. Three features characterize the classic syndrome: an unusual, almost indescribable sensation in the lower extremities; an irresistible urge to move the legs, and the exclusive occurrence of the symptoms at rest, with their relief by movement. Restless legs syndrome may cause severe insomnia. Variants of the syndrome, as well as numerous associated conditions, have been described. The etiology is unknown. Clonazepam and carbamazepine are reported to be effective in treating this syndrome.