It is discomfort rather than pain. They occur when the legs are at rest, such as in the car, at bedtime or in the movies. Others don't wake up but kick so much they waken their spouse. Mild forms do occur that can be observed in the sleep lab but do not disturb the person. No abnormality can be found on examining the nervous system, the muscles or on doing any lab tests.
Men have it more than women, but it is common in middle-aged women.
About a third have a family history of similar problems. It does not alter one's life span. Most patients with restless legs have movements during sleep but most patients with sleep disorders do not have restless legs. The movements are precipitated by rest and relieved by activity. They occur or are worse during the evening or later at night and may cause insomnia.