Sleep disturbances are fairly common in childhood. Many children resist going to bed, and parents frequently give in just to get the child to sleep by allowing the child to sleep in the parents' bed or allowing them to stay up late. Unfortunately, children learn remarkably well how to get what they want, and the parents' concessions only make the problem worse. Learned behavior (behavioral insomnia, dyssomnia) is the root of many sleep disturbances in young children.Other types of sleep disturbance in children fall into the category of sleep disruptions, such as nightmares and night terrors.A nightmare is a scary or disturbing dream that usually awakens the child and causes agitation about the content of the dream. Nightmares occur during rapid eye movement (REM) sleep. Many children and adults have an occasional nightmare; recurrent or frequent nightmares, however, may be indicative of an ongoing stress in the child's life. Night terrors (pavor nocturnus) are non-REM phenomena seen less commonly than nightmares, occurring in 1% to 6% of all children. The child will be described as apparently awake but unresponsive; they can have evidence of autonomic arousal such as tachycardia, sweating, and tachypnea, and appear frightened and agitated. Attempts at calming the child are usually not effective, and the child will eventually go back to sleep. Although usually a problem in early childhood, night terrors can sometimes continue through adolescence.Somnambulism, or sleepwalking, occurs in 15% of children and is described as recurrent episodes of rising from bed and walking around. The child is typically hard to arouse and will have amnesia after the event. This usually happens in the first third of the sleep cycle, during stage 4 non- REM sleep. Somniloquy, or sleep talking, can occur at any sleep stage and is seen in all ages.