You're awake and you're safe. Ben has experienced a nightmare , a strong, unpleasant dream. Nightmares may be upsetting, but they are not real and can't harm you. While you sleep , your brain keeps going through these stages, including the REM phase, which accounts for about a quarter of your total sleep. And while you actually dream throughout the night, the dreams you have during REM sleep are stronger and more intense than during the other stages.
Nightmares are most likely to occur during REM sleep.
Nightmares may not be all bad - your brain may be trying to tell you to pay attention to something that's bothering you when you're awake. They may even give you creative ideas, as they did for Mary Shelley, the author of Frankenstein. She wrote the classic story after a vivid nightmare. No one is sure what causes nightmares, but there are several theories. Some people believe that eating spicy or rich food or drinking caffeine just before you go to sleep will cause bad dreams.