Sleep Disorders - Periodic Limb Movement Disorder (PLMD)

A sleeping disorder that affects the limbs as well as a person’s ability to sleep at night and function normally during the day is called Periodic Limb Movement Disorder (PLMD). Most people with this disorder are not aware of these movements.

PLMD most often occurs in the legs, but it can also affect the arms. As the name suggests, limb movements occur at regular intervals, usually every 30 seconds. Periodic limb movements of five or more times an hour may prevent a person from sleeping. People often complain of difficulty falling asleep or difficulty staying asleep. This can lead to daytime sleepiness and unhappy bedpartners.

PLMD is rare in people under 30 years of age, but becomes more common as people age. PLMD affects one-third of people age 50 to 65, and almost one-half of people over age 65. Both men and women are equally likely to be affected, and PLMD contributes to the inability to sleep in two out of every ten people who have been diagnosed with insomnia.