Nightmares are frightening dreams that occur during rapid eye movement (REM) sleep .

A child having a nightmare can awaken fully and can vividly recall the details of the dream. Nightmares are not a cause for alarm, unless they occur very often.

They can occur more often during times of stress, or even when the child has seen a video containing aggressive content. If nightmares occur often, parents can keep a diary to see if they can identify the cause.
Any suggestions to prevent such a problems is the children?