Waking up in a cold sweat from a bad dream is certainly frightening in the moment, but health experts say that nightmares can also have more long-lasting effects on our health.
“It’s possible that nightmares can impact both mental and physical health, especially if the person gets more distressed because of having nightmares or if having nightmares greatly affects the person’s sleeping patterns,” psychologist Maria Lentzou tells Teen Vogue. In fact, having frequent nightmares may increase our risk for certain health conditions.
We’re all susceptible to nightmares every once in a while, but Sleep.org reports that up to 10% of people experience nightmares on a weekly basis. With the potential to impact our mental health, nightmares have been linked with anxiety, depression, bipolar disorder, schizophrenia, and post-traumatic stress disorder (PTSD). In addition, sleep deprivation can set in when nightmares continuously interfere with our quality of sleep, which can increase one’s risk of cardiovascular disease and obesity, according to WebMD.
The relationship between nightmares and cortisol
Jolting us out of sleep, nightmares can immediately put our bodies in a state of stress, according to experts at Stanford Health Care. In addition to increased sweating and a racing heart, some evidence suggests that nightmares can also heighten cortisol release first thing in the morning — otherwise known as the stress hormone (via Mindbodygreen). Occurring within one hour of waking up, our body’s cortisol awakening response (CAR) may help us meet the demands of the day, according to research published in PLOS ONE. However, too much of this stress hormone can impact mood, gut health, and more, warns Mindbodygreen.
In a 2024 study published in Psychoneuroendocrinology, researchers looked at the effect of nightmares versus neutral dreams on the cortisol awakening response (CAR) of 30 healthy participants who frequently experienced nightmares. At the end of the two-week study period, it was found that nightmares temporarily elevated participant cortisol levels. As opposed to neutral dreams, nightmares were also found to negatively impact quality of sleep, and result in more health complaints.
