In contrast, those whose RLS is not related to any other medical condition and whose onset is at an early age show a very slow progression of the disorder and many years may pass before symptoms occur regularly. A family history of the condition is seen in approximately 50 percent of such cases, suggesting a genetic form of the disorder. People with familial RLS tend to be younger when symptoms start and have a slower progression of the condition. Once iron levels or anemia is corrected, patients may see a reduction in symptoms. Treating the underlying condition often provides relief from RLS symptoms.
Some pregnant women experience RLS, especially in their last trimester.
For most of these women, symptoms usually disappear within 4 weeks after delivery. Patients can talk with their physicians about the possibility of changing medications. Some studies have shown that a reduction or complete elimination of such substances may relieve symptoms, although it remains unclear whether elimination of such substances can prevent RLS symptoms from occurring at all. The disorder is diagnosed clinically by evaluating the patient's history and symptoms. Despite a clear description of clinical features, the condition is often misdiagnosed or underdiagnosed.