Which comes first, the nightmare or the illness?
It’s hard to say. But one thing is certain: your dreams, and particularly your nightmarish ones, are intimately connected with both your mental and physical health.
According to Bill Fish, a sleep science coach and co-founder of the online sleep resource Tuck.com, the average person has at least one nightmare a week.
But if nightmares are seriously disrupting your sleep, something else might be happening.
It’s kind of a chicken-and-egg thing. On the one hand, frequent nightmares can be caused by a mental health condition like post-traumatic stress disorder (PTSD).
In PTSD, the mind unconsciously takes traumatic events and “plays around with them, tries to make sense of them,” says Neil Greenberg, professor of defense mental health at King’s College London.
On the other hand, nightmares can be a clear warning sign of more serious health conditions to come.
Sleep cycles: preparing for REM sleep
When nightmares occur, they can interrupt the Rapid Eye Movement (REM) phase of our sleep cycle. It’s hard to overestimate the importance of REM sleep or the damage that can be done when it’s routinely disrupted by nightmares.
But before REM occurs, we must go through three sleep stages:
Stage 1 – Your eyes are closed, but you are still awake.
Stage 2 – Light sleep. Heart rate slows and body temperature drops as your body prepares for deep sleep.
Stage 3 – Deep sleep. Here the body repairs and regrows tissue, strengthens your immune system, and builds bone and muscle. It’s hard to wake someone from this stage of sleep.
REM sleep: protection for your brain
After Stage 3 comes REM sleep. Your first period of REM sleep lasts about 10 minutes, and gets progressively longer during the night, with the final one near morning lasting perhaps an hour.
REM sleep is where memories are formed. While this may not seem crucial to health, scientists know that this type of neural activity keeps the brain plastic, or flexible. This state of plasticity has been connected with preventing both Parkinson’s and Alzheimer’s disease.
How nightmares can be harmful
In fact, a chronic disturbance in REM sleep, known as REM sleep behavior disorder, is a good predictor of Parkinson’s disease.
In a recent University of Toronto study, 80 percent of REM sleep disorder patients developed Parkinson’s.
A person with REM sleep disorder not only has frequent nightmares, but the normal muscle paralysis that occurs during REM sleep does not occur. This allows the person to jump out of bed and act out dreams, sometimes violently, and often injure to themselves or others.
The causes of this disorder are unclear, but some possibilities are:
- PTSD or recent trauma
- Adverse reaction to antidepressants, particularly SSRIs, also known to increase your risk of heart attack and stroke.
- Breathing problems, including sleep apnea and asthma
In addition, frequent nightmares, especially in the elderly, have been associated with irregular heartbeats and chest pains.
We already know that, statistically, most heart attacks occur between 4 a.m. and 10 a.m. While there is no definite link between interrupted REM sleep and heart attacks, it makes sense to suspect that the two are connected.
Many nightmares also occur during early morning REM sleep. This is actually a stressful time for the body. It’s getting ready to release cortisol, our stress hormone, to get us ready to face the day.
Other factors that can cause nightmares
Even if you don’t have REM sleep behavior disorder, your health can be affected by the interrupted REM sleep caused by nightmares.
Here are a few other things that could be behind your bad dreams:
- Sleep Disorders: People with sleep apnea, restless leg syndrome, and other sleep disorders are more likely to experience nightmares.
- Migraines: Migraine headaches may be linked with more recurrent dreams and nightmares.
- Pain: The sensation of pain can work its way into your dreams. Sleep can become stressful rather than restorative if the pain is constantly present.
What you can do
If frequent nightmares are leaving you exhausted on a daily basis and seriously disrupting your life, and especially if any of the above three factors are present, talk to your doctor.
Sometimes, medication can help control REM sleep behavior disorder, but here are some things to know, and strategies to try, before you resort to medication:
- Practice good sleep hygiene by controlling the noise and light in your bedroom
- Take time to de-stress before bed. Yoga, relaxing music and scents, and low lighting all help set the stage for a good night of sleep.
- Using a journal to write down your nightmares has been proven to help. Ask about Image Rehearsal Therapy, a form of treatment approved by the American Academy of Sleep Medicine. It allows you to write down your nightmare, but give it a more positive ending.
- Check your medications. Certain drugs are known to induce nightmares. These include SSRIs, beta blockers (for hypertension) and tricyclic antidepressants such as amitriptyline.