Just about everyone experiences nightmares sometime during their life, but not everyone has the disturbing experience of having a night terror. This is a different situation from the more common nightmare. With night terrors people may be extremely disturbed and show this by crying out, even screaming, without being fully awake. In most cases, the person’s eyes are open but they are not aware of their immediate surroundings.
People who experience this probably will not respond if someone comes into the room to ask what the trouble is. Research has shown the unsettling fact that thousands of children experience such night terrors, with the start of the episodes beginning when the child is very young (preschool). The length of these events varies from a matter of minutes to nearly an hour, though shorter times seem to be more common. In most cases, the individual returns to a comfortable sleep without remembering the episode.
This differs from nightmares in significant ways. A nightmare generally results in the person becoming fully awake. That person also remembers some or most of the dream, which is what a nightmare is. The difference between a dream and nightmare is the events that seem to be happening and remain in the memory after the person wakes up.
The biological/neurological difference is that night terrors might well occur at a different time, even during the transition from one sleep stage to another. A nightmare can occur during the rapid eye movement phase later during a sleep session. Night terrors normally occur much earlier in the night. This varies with individuals but the pattern is fairly well set.
One of the noticeable physical changes that occurs is the increase in heart rate. According to several sleep studies, a person experiencing a night terror has a heart rate that is two or three times faster than normal. The heart will often beat even faster than the heart would beat during a very stressful situation in waking hours. This is of concern to doctors because of the extra stress placed on the body.
Researchers have long studied this phenomenon, trying to uncover the causes of night terrors. Since about 15 out of every 100 young people have this malady sometime during their life, finding the causes can be quite important. Some scientists believe that night terror events follow stressful situations in the immediate time before sleep. Some studies have found that certain medications “unlock” certain activities in the brain and this leads to unusual sleep-time experiences.
A few people have experienced night terrors and remembered disconnected pieces of the episode. Researchers have found that many of these remembered events contain similar images such as particular animals or the presence of physical danger. There doesn’t seem to be much connection to daytime fears or phobias, studies show.
A person who comes into the room where someone is experiencing night terrors should do their best to remain calm then try to assure the sleeping person that everything is alright. Studies have shown that physical contact should not be forced during this time. Anyone coming upon such an episode should proceed carefully and quietly.