Problems involving disruption in sleep pattern or inability to sleep.

Sleep is a period of decreased activity and muscle relaxation, characterized by patterns of deep sleep (where brain waves are slower, called non-rapid eye movement sleep) alternating with dreaming sleep, known as rapid eye movement (REM) sleep. Sleep restores energy to the body, especially to the brain and nervous system.

Sleep disorders common in childhood include enuresis (bedwetting), pavor nocturnus (night terrors), and somnabulism (sleepwalking). Less common in children are insomnia (sleeplessness, trouble falling, and staying asleep), and narcolepsy (difficulty staying awake).