(HealthDay News) -- A night terror may cause a child to wake up sweating and screaming, and parents might think their child is having a "super" nightmare.

But a night terror is different from a nightmare, the Nemours Foundation says. It occurs while the child is in a deep sleep, and the child usually has no recollection of what caused the sudden outbreak of fear.

Night terrors are rare, affecting only 3 percent to 6 percent of children, the foundation says. It says common triggers of night terrors include:

• Having a family member who had night terrors.
• Having an immature central nervous system.
• Being stressed out or over-tired.
• Having a change in sleep environment, such as when spending the night away from home.
• Being on a new medication.