The nightmare realm: What if it's more than just a bad dream?

Bad dreams may frighten children, but they are normal. Night terrors are more intense — the child may scream or thrash about — and will also frighten the parents, says Geraldine Walsh.

At the age of four, I started to have such vivid nightmares that I still remember almost every detail. They began with a fever and a dream of being chased down a cartoon hill by an ever-stretching, ever-looming arm.