It has four primary characteristics. Symptoms are worse at, or confined to, periods of rest.
Symptoms are worse in the evening or nighttime.
This can lead to difficulty remaining asleep. PLMS are jerks that occur 20 to 30 seconds, on and off throughout the night. People who have PLMS are usually unaware of these disruptive movements or the partial arousal that disrupt their sleep. Because it's often difficult for people with RLS to fall and stay asleep, they may be unusually tired during the day. It is thought genetics are a factor and the presence of a secondary disorder may also contribute to its occurrence.