Restless legs syndrome (RLS) is a chronic neurological disorder characterized by an urge to move the legs at night when at rest. RLS can lead to a sleep deprivation, increased falling risk, daytime sleepiness, depression and decreased quality of life. Dopamine agonists, alpha-2-delta ligands and opiates are key medications for RLS. The natural course of RLS is very heterogeneous with a risk of increasing the severity of symptoms over the years despite the use of drugs and recommended dosages. Many comorbidities can make RLS worse. Augmentation syndrome is the main complication of dopamine agonists. However, only a few studies have addressed the clinical, biological and pharmacological factors associated with the evolution of the severity of RLS. The objective of this study is to assess the evolution of RLS symptoms severity as function of RLS phenotype, comorbidities and RLS medication, in large cohort of members of the French RLS association and other European RLS association.