Restless legs syndrome (RLS) is a neurologic disorder. It is characterized by:

  • Unpleasant sensations in the legs
  • An irresistible urge to move the legs

The cause of primary RLS is unknown. RLS may have some genetic component. In some cases, it may be caused by other conditions or certain medications. This is called secondary RLS.

Many people with RLS also have periodic limb movement disorder (PLMD). This is a related motor disorder characterized by:

  • Involuntary, repetitive, jerking movements
  • Interrupted sleep because of periodic leg movements