Doctors don't know the definite cause of restless legs syndrome; however, evidence suggests that hereditary factors, pregnancy, some chronic diseases and certain medications increase the risk of the condition, WebMD claims. Additionally, iron deficiency and nerve damage can trigger the condition.
Approximately 50 percent of people with restless legs syndrome have a relative suffering with the condition, which suggests that genetics play a role, according to WebMD. Chronic diseases, such as Parkinson's disease, kidney failure, diabetes and peripheral neuropathy, increase the risk. Cold and allergy medications, some antidepressants, some anti-anxiety medications and antihistamines may play a role. Women sometimes experience the condition during the final trimester of their pregnancy, and the symptoms disappear around one month after delivery.
Research indicates that iron deficiency causes restless legs, Healthline highlights. This may be due to iron playing a role in dopamine production, which in turn helps the brain control movements. Such research may explain why those who have chronic conditions, such as Parkinson's and kidney failure, experience restless legs syndrome, as both affect the body's iron uptake. Additionally, accidents and conditions such as diabetes and rheumatoid arthritis can result in nerve damage, which may lead to secondary restless legs syndrome.
Although this condition affects people of all ages, it's more common in women than men, Healthline claims. Additionally, diagnosis usually occurs later in life, and those with Northern European ancestors have a predisposition to the condition.