A child screaming and crying as though he's in pain in the middle of the night is frightening for parents, especially when the child seems to be awake and aware, but isn't able to say what the problem is.
These startling episodes are called night terrors, and they can occur in an otherwise healthy child between the ages of 2 and 12 who has no other obvious source of a problem like fever, earache, or other obvious source of pain. When asked about the events of the previous night, children who are old enough to talk about it typically have no recollection. In fact, sleep terrors are often more disturbing to the observer than they are to the child, and the more you try to find a solution, the more it just frustrates everyone.
Although night terrors can occur at any time, even during naps, they typically happen closer to midnight because they are related to slow wave, non-REM sleep, as opposed to nightmares, which usually occur closer to morning, when more REM sleep and accompanying dreams occur, as nightmares are dream-related.
If night terrors are happening frequently and predictably enough, you can try waking your child for a few minutes about 15 to 20 minutes before they typically happen. But most of the time they are not frequent enough to warrant disturbing sleep on a regular basis.
It is thought that anything that leads to increased slow-wave sleep can bring the episodes on, such as being overtired, sick and not sleeping as well as usual, or taking medicines with antihistamines, such as cold medicines that bring on slow-wave sleep more quickly
