Most of us are walking around with a false understanding of what nightmares really are, suggests new research, which looked at the content of 10,000 dreams. While nightmares are more common among children (about 50% of kids have them), 5-6% of adults also experience them, and they can lead to sleep disorders and insomnia.

There's both an emotional and content-related difference between bad dreams and nightmares, with the latter having a stronger emotional impact, according to a study at the University of Montreal.

"Physical aggression is the most frequently reported theme in nightmares. Moreover, nightmares become so intense they will wake you up. Bad dreams, on the other hand, are especially haunted by interpersonal conflicts," Geneviève Robert and Antonio Zadra, psychology researchers at the University of Montréal, wrote in a recent issue of Sleep, after reading and compiling data from the dream journals of 572 individuals.

And while fear is the most common emotion in a nightmare (death, health concerns and threats are common sources, says Robert), nightmares can also include anxiety, confusion, guilt or sadness.

Often, a nightmare will cause the dreamer to wake up, disturbing sleep. "Sometimes, it is the feeling of a threat or a ominous atmosphere that causes the person to awaken. I'm thinking of one narrative, in which the person saw an owl on a branch and was absolutely terrified," Robert told Science Daily. But just because your nightmares don't 'seem' scary to other people doesn't mean they don't impact you or the way you feel.

While nightmares can be upsetting, and researchers still aren't sure about all the reasons behind dreams (whether bad or pleasant) the good news is that they can be treated. Visualization techniques and lucid dreaming can enpower dreamers to fight back, ameliorate or leave distressing situations in their dreams. By being aware of oneself on one's dreams, the scenario can be changed or moved out of.

If nightmares are frequent enough to disturb sleep (or are scary enough to keep people from wanting to go to sleep), and lead to difficulty working or caring for self or family, they could be classified as nightmare disorder by the Diagnostic and Statistical Manual. Nightmares that are repetitive and may be related to previously experienced trauma are most often in this category. The full description for the disorder which should be treated by a professional is:

DSM-IV criteria for nightmare disorder

  • Repeated awakening from sleep or naps with detailed recall of extended and extremely frightening dreams. The nightmare usually involves a significant threat to survival, security or self-esteem.
  • Awakening from sleep generally occurs during the second half of the sleep period.
  • On awakening, the sufferer is usually rapidly orientated and alert.
  • The dream experience, or the sleep disturbance caused by it, leads to clinically significant distress or impairment of social, occupational or other important areas of functioning.
  • The nightmares are not exclusively associated with another mental disorder (eg delirium, post-traumatic stress disorder (PTSD)) and are not due to the effects of a substance on the body (eg medication, drugs of abuse, drug or alcohol withdrawal) or a medical condition.
I have nightmares whenever I have a strong fever; do you have nightmares regularly?

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