Why Nightmares?
Stressful things that happen during the day can turn dreams into nightmares. Nightmares may be a way to relieve the pressures of the day. This usually means dealing with things most kids have to face at one time or another: problems at home, problems at school, and stress from sports or schoolwork. Sometimes major changes, such as moving or the illness or death of a loved one, can cause stress that leads to nightmares.
Another thing that may cause nightmares is watching scary movies or reading scary books, especially before you go to bed.
Sometimes if you are sick, especially with a high fever, you may have nightmares. Certain medications also can cause nightmares. Let your parents and doctor know if you notice you are having more nightmares around the time you started a new medicine.