- Nightmares cause biological stress. Frequent nightmares strain the body and brain and could be related to developing some chronic conditions.
- Persistent nightmares may be linked with risk of accelerated aging and earlier death, according to multiple studies. Researchers are trying to determine if treating nightmares could slow down aging.
- Today, frequent nightmares have their own diagnosis, called nightmare disorder, which up to 8 percent of people suffer. Researchers suggest therapies to alleviate nightmares.
Running from a faceless monster, falling from a great height. We’ve all found ourselves upright in bed at 3 a.m., our sheets soaked and hearts pounding. “It was just a bad dream,” we say in relief.
But now there’s new research to suggest that bad dream might portend something much scarier.
Weekly nightmares appear to be linked to a tripled risk of premature death, according to a new study presented at the European Academy of Neurology in Helsinki last month. People who experience frequent bad dreams also showed “significantly accelerated biological aging,” meaning their bodies demonstrated more wear, tear, and decline than a healthy person of the same age. These findings held up regardless of age, sex, or ethnicity.
The research was conducted by Dr. Abidemi Otaiku, Ph.D., a clinical research fellow in the department of brain sciences at Imperial College London, who analyzed data from 2,429 children aged eight to 10 and 183,012 adults aged 26 to 86 who had participated in a long-term U.S. health study.
Adults reporting weekly nightmares were more than three times as likely to die before age 70, the data showed. Frequent nightmares were a stronger predictor of premature death than other risk factors like smoking, obesity, and poor nutrition.
Could this finding actually be the result of other conditions associated with nightmares, diseases like heart disease, diabetes, and dementia?
“People with nightmares do have a higher number of chronic conditions,” Otaiku says. “But even when I did take these into account, the link between nightmares and premature death remained significant.”
This wasn’t the first time Otaiku has turned up evidence that our fictional visions can lead to very real health impacts.
In the last few years, his research has found that older adults who have nightmares every week are twice as likely to develop Parkinson’s and four times as likely to develop dementia in the next decade. In a 2023 study, Otaiku found that children who had frequent nightmares between ages of 7 and 11 were more likely to develop Parkinson’s Disease or be cognitively impaired by the time they turned 50.
Otaiku isn’t the only scientist exploring the connection between nightmares and poor physical health. One 2023 study found that nightmares could represent an independent risk factor for cardiovascular disease. Another found that nightmares may signal the flare-up of autoimmune disorders like rheumatoid arthritis or lupus.
All of these findings made Otaiku want to figure out whether accelerated aging itself might be one pathway through which nightmares can lead to adverse health conditions, he explained.
For the current study, he assessed participants’ biological aging by looking at the length of their telomeres, the DNA sequences that cap the end of chromosomes and prevent them from fraying, much like the plastic tip on the end of a shoelace. Scientists believe that telomere length is a reliable way to determine whether a person’s cells are aging at a faster rate than their actual age might suggest.
Otaiku found that children and adults with more frequent nightmares had shorter telomeres and were exhibiting faster biological aging than their healthy peers.
Bad dreams could actually lead to nightmarish health outcomes, the research suggests.
“Our sleeping brains cannot distinguish dreams from reality.” Otaiku said in a press release. “That’s why nightmares often wake us up … because our fight-or-flight response has been triggered. This stress reaction can be even more intense than anything we experience while awake.”
Part of that reaction is the body’s release of cortisol, a stress hormone closely linked with faster cellular aging.
Nightmares can also negatively affect sleep quality and duration, “impairing the body’s essential overnight cellular restoration and repair,” Otaiku explained. “The combined effects of chronic stress and disrupted sleep likely contribute to the accelerated aging of our cells and bodies.”
Otaiku says that this new wave of sleep research is changing the way that doctors like himself look at nightmares in their patients.
“Twenty or thirty years ago we saw nightmares as a symptom of anxiety or PTSD,” he says. Today, frequent nightmares have their own diagnosis.
It’s believed about two to eight percent of the U.S. population suffers from nightmare disorder, a condition characterized by frequent bad dreams that interfere with daily functioning and quality of life.
“So we’ve moved from nightmares from being a symptom to being a disorder—and now to being a risk factor for other conditions,” Otaiku says.
The scientist, who says he experienced frequent nightmares as a kid, plans to continue research that he hopes will clarify whether the link between bad dreams and ill health is correlative or causal. He’d also like to investigate whether treating nightmares could slow down aging.
He says simple measures like the ones he used as a kid—avoiding scary books and movies—can help nip nightmares in the bud, as well as basic stress management and sleep hygiene protocols. For severe cases of nightmare disorder, a number of cognitive behavioral therapies are available to help sufferers have better dreams, get better sleep, and, maybe, live longer lives.
Ashley Stimpson is a freelance journalist who writes most often about science, conservation, and the outdoors. Her work has appeared in the Guardian, WIRED, Nat Geo, Atlas Obscura, and elsewhere. She lives in Columbia, Maryland, with her partner, their greyhound, and a very bad cat.