In some people, the walking, talking, and other body functions normally suppressed during sleep emerge during certain sleep stages.

Alternatively, the paralysis or vivid images usually experienced during dreaming may persist after awakening. These…

Narcolepsy’s main symptom is excessive and overwhelming daytime sleepiness, even after adequate nighttime sleep. In addition, nighttime sleep may be fragmented by frequent awakenings. People who have narcolepsy often fall asleep at inappropriate times and places.

Restless legs syndrome (RLS) causes an unpleasant prickling or tingling in the legs, especially in the calves, that is relieved by moving or massaging them. This sensation creates a need to stretch or…

• Another disease or mood disorder. The most common causes of insomnia are depression and/or anxiety disorders. Neurological disorders such as Alzheimer’s or Parkinson’s…