Two or three percent of all children will experience episodes of night terrors. Yet by the time they reach school age, most children will have outgrown these generally harmless events. As the brain matures and a child's sleep pattern matures, the terrors go away. This usually happens by age six. A night terror is not the same thing as a nightmare.
Nightmares occur during the dream phase of sleep known as REM sleep.
The circumstances of the nightmare will frighten the child, who usually will wake up with a vivid memory of a long movie-like dream. During a night terror, which may last anywhere from a few minutes to an hour, the child is still asleep. Her eyes may be open, but she is not awake. When she does wake up, she'll have no recollection of the episode other than a sense of fear. It's helpful to know that although these events may be disturbing for you, night terrors themselves are not harmful to your child.