What Nightmares Can Reveal About Your Health

(This article previously appeared on Grandparents.com.)

Your plane is going down; someone is stalking you but you can't make your legs move; your house is on fire and there's no way out. GAAAAAHHH! Nightmares are often the result of normal things like garden-variety stress — or they could be a signal of a physical health issue.

All dreams occur during REM (rapid eye movement) sleep, which is essential to mental health. "You need REM sleep to integrate current emotional material into long-term memory," explains Patrick McNamara, associate professor of neurology, Boston University School of Medicine. In other words, your brain uses dreams to make sense of what you experience every day.

"If you disrupt REM sleep, whether through respiratory problems, intense hormonal changes or stress, that emotional content just sits there and irritates the brain. You get nightmares as a result," notes McNamara. These dark dreams usually occur later in the night, and women get them more often than men.

In general, you shouldn't worry about the content of your nightmares, says McNamara. Lots of people have bizarre dreams. But if you are having nightmares often, talk to your doctor. Most times they are a result of stress, anxiety, certain medications, family history, and hormonal changes. However, other more serious issues could be the cause.

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A 2003 Swedish study discovered that in elderly men and women, increased nightmares were associated with an increase in irregular heartbeats, as well as spasmodic chest pain. That same study also found that the occurrence of chest pain and irregular heart beats increased in 40- to 64-year-old women with frequent nightmares and poor sleep. The occurrence of spasmodic chest pain was further increased after menopause.

Most heart attacks occur in the early morning when REM is occurring, because REM places stress on the body. "When we switch into REM sleep, our breathing becomes more rapid, irregular, and shallow, our eyes jerk rapidly in various directions, and our limb muscles become temporarily paralyzed," says the National Institute of Neurological Disorders and Stroke. "Heart rate increases, blood pressure rises, and males develop penile erections. When people awaken during REM sleep, they often describe bizarre and illogical tales."

So it's not the nightmares that are causing physical stress but rather the REM sleep, which in turn causes the nightmares.

"REM sleep is a stressor because it is stimulating your amygdala, the part of your brain responsible for emotions. Combine this overactive amygdala with poor cardiac health, and you are much more vulnerable to having a heart attack. It's as if a person with cardiac problems is riding up a hill. It makes the autonomic nervous system overreact," says McNamara. (Except in this one instance, nightmares cannot physically harm you.)

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Three recent studies published in The Lancet Neurology have shown that people with REM sleep disorders who experience intense nightmares that manifest physically during sleep (ie: screaming, crying, punching, and kicking) are at risk for developing Parkinson's Disease and other neurodegenerative diseases.

Healthy people experience a paralysis during REM sleep. People with Parkinson's and related neurodegenerative disorders, however, lose the ability to maintain paralysis in REM sleep. This allows them to act out their dreams, which people who don't have neurogegenerative disorders generally cannot do.

A new English study found that children who suffer from frequent nightmares or bouts of night terrors may be at an increased risk of psychotic experiences in adolescence. "Our recent research that looked at being bullied and nightmares indicate that experiences during the day are still processed at night and this alters stress responses physiologically. Both of these have been related to increased risk of developing mental health problems," says Dieter Wolke, lead author of the study, Professor of Developmental Psychology and Individual Differences, The University of Warwick Department of Psychology.

However, we're not talking about the occasional nightmare: Parents should be concerned when the nightmares occur regularly — over months and even years, adds Wolke.

If your nightmares are increasing and the content is often about not being able to breathe, have your healthcare professional check you for sleep apnea, a chronic condition that occurs when you have pauses in your breathing or shallow breaths while asleep.

Sleep apnea wreaks havoc with your REM sleep due to lack of oxygen. Dr. William Kohler, medical director of the Florida Sleep Institute, Spring Hill, explains, "Patients have had terrifying dreams of drowning or suffocation. In reality, their airway is blocked off."

A recent study published in Sleep Medicine found that the nightmares disappeared in 91 percent of patients with sleep apnea who were treated with continuous positive airway pressure (CPAP) therapy.

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If your nightmares are not a symptom of illness, there are various therapies to help stop them:

You are led into a hypnotic trance by a trained therapist, during which the therapist makes suggestions for reframing of the dream. You'll be instructed to tell yourself when you have a nightmare, "I've had nightmares before and nothing bad has ever happened, nothing ever will happen."

In IRT, you are asked to confront the terrifying images in a nightmare in a safe place, such as a therapist's office. You draw, describe or write about the scary thing, and then confront it, look at it, talk directly to it and challenge it. Then you draw/describe/ write about it again, and make it less scary by rewriting the script.

That person stalking you is really trying to give you a present, for example. "This does work but it takes time. You have to do it for many weeks," says McNamara.

If the nightmares are severe due to post-traumatic stress disorder, a study published in the American Journal of Psychiatry showed that the drug prazosin is effective in diminishing frequency, severity and sleep disruption.