Answer:

Nightmares can have causes that aren't due to underlying disease. In children, it's a regular stage of the development process. Causes include scary movies and books, individual experiences or medication side effects.

Step-by-step explanation:

Nightmares, or bad dreams, are a type of dream that causes you to feel anxiety, fear or terror. Typically, a person will wake up during or just after having a nightmare and he or she will be able to remember all or part of the bad dream clearly

Nightmare is a frightening dreams, it causes including scary movies, books etc.

hope it is helpful for u dear