Approximately 30 percent of people with fibromyalgia also have restless leg syndrome
(RLS). RLS is a neurological disorder characterized by unpleasant sensations in the legs and an uncontrollable urge to move when at rest. People describe these unpleasant sensations as burning, creeping, tugging, or like insects crawling inside the legs. The sensations may range in severity from uncomfortable to irritating to painful.
The most distinctive feature of RLS is that lying down and trying to relax actually activates the symptoms, which can significantly interfere with sleep. Because moving the legs relieves the discomfort, people with RLS often keep their legs in motion. They toss and turn in bed and often find they have to get up and walk to relieve the sensations.
More than 80 percent of people with RLS also experience a more common condition known as periodic limb movement disorder (PLMD), which is characterized by involuntary twitching or jerking of the legs during sleep. These movements typically occur every 10 to 60 seconds and may continue throughout the night, causing repeated awakening and severely disrupting sleep.
The cause of both RLS and PLMD remains a mystery. Both, however, result in poor sleep quality, leaving patients with exhaustion, poor concentration, and an inability to accomplish normal daily tasks.