In people who suffer from periodic limb movement disorder (PLMD), the legs and sometimes the arms twitch repeatedly during the night, causing micro-awakenings that can disrupt sleep and lead to daytime drowsiness. People with this disorder are not aware of their movements, but they may disturb their partners, who feel as if they are being kicked.
This disorder is common in people with RLS, but it can also occur alone or with other sleep disorders, such as sleep apnea and insomnia. It is estimated to affect 10-15% of the population.