Restless leg syndrome is caused by:

Secondary restless leg syndrome can occur due to chronic renal failure, pregnancy, anemia, ferritin deficiency and peripheral neuropathy. It could be due to disordered dopamine function along with abnormality of iron metabolism. Restless leg syndrome is a neurologic disorder characterised by the presence of: An urge to move the legs, usually caused or accompanied by an unpleasant sensation in the legs The symptoms usually begin or worsen with rest The symptoms worsens during the evening or night. There is paial or complete relief by movement Ref: Olanow C.W., Schapira A.H. (2012). Chapter 372. Parkinson's Disease and Other Movement Disorders. In D.L. Longo, A.S. Fauci, D.L. Kasper, S.L. Hauser, J.L. Jameson, J. Loscalzo (Eds), Harrison's Principles of Internal Medicine, 18e.