Understanding the Science behind Nightmares

woman sleeping in a wooden room

Waking up drenched in sweat, gripping the sheets in the middle of the night is a well-known concept for many people. And the culprit responsible for this is nightmares. A nightmare can wake a person up in a state of chronic anxiety and fear, while the world around them is fast asleep.

Nightmares can affect people of all ages, but children are more commonly the victim of the terrorizing sleep visions. However, most children grow out of it eventually, whereas if adults have nightmares, they might be in for a life-long chain of encounters with panic-inducing visions.

“It’s the stuff nightmares are made of” – A common expression we all have heard before, but what are nightmares exactly? Why do we have them and what can we do about them? Let’s delve further into this phenomenon and find out. 


Back in the 1700s, a nightmare was defined as a disease characterized by having strong emotional responses due to a person’s thoughts during sleep. That is, people used to believe that when a person would think about having a weight upon themselves during their sleep, they would experience symptoms of nightmares. The said definition was first printed in the Universal Etymological English Dictionary published in 1721 by Nathan Bailey.  

Although now people don’t often exchange the definition of a nightmare, the general perception about a nightmare remains the same. That is, a nightmare evokes strong emotional and physiological responses in humans.

Understanding Nightmares

Nightmares are an extension of a person’s fears and worries. However, the depiction of those fears and concerns in nightmares can be jarring and leave a person in a state of pain. According to the American Academy of Sleep, 10-50% of kids between the ages of 5-7 can be affected by nightmares to such an extent that they might end up disturbing their parents or a sibling to manage their fear.

Children’s nightmares are typically associated with a scary TV show or a film or any significant anxiety-evoking life event such as a death in the family or starting a new school. What a child sees in a nightmare is, in most cases, a reflection of how much they are affected by a harrowing life event or a scary story. Although the trauma of having a nightmare in kids is no less severe than that experienced by adults, children outgrow nightmares as they age. But if adults are on the receiving end of nightmares, then the chances are that they might never outgrow them.

The American Academy of Sleep reports that nightmares plague only 2-8% of the adult population. Adult nightmares are similar to children’s nightmares in most aspects. The nightmares an adult experiences are also a continuation of their thinking process. According to Lauri Quinn Loewenberg, the author of Dream on it, Unlock your Dreams and Change your Life; a nightmare is the continuation of our chain of thoughts from the day. Anything that disturbs a person during the day can disturb them during the night as well. The only difference is that in the day they can distract themselves while in the night, during sleep, they can’t distract themselves. And henceforth, nightmares can be overpowering and overwhelming.

Even though nightmares stem from the daily stresses, worries, and banes of life, they are not always the cause behind a nightmare. In some cases, poor eating habits can also cause bad dreams to occur. Indulging in a late-night snack or a carbohydrate-rich meal before going to bed can lead to a terror episode during the night.

For some people, hidden food allergies can also cause nightmares. Sometimes, it’s possible that people might not be aware of a food allergy that they might have. In such a case, that unknown food allergy can lead to disturbing nightmares.

Sometimes nightmares may also disturb a person while they are asleep if they have a sleep disorder. Some sleep disorders like sleep apnea or restless leg syndrome can induce nightmares in a person’s vision during sleep. Furthermore, having psychological disorders such as depression or anxiety can be the reason behind nightmares.

Brain and Nightmares

Typically, nightmares occur in the third phase of the night when REM (Rapid eye movement) is the strongest. There are four sleep stages that a person goes through. The first is sleep onset, the second stage is light sleep, and the third is the deep sleep stage, and the fourth stage is the REM stage.

In routine, rapid eye movement occurs every ninety minutes during the night and is associated with high brain activity, rapid eye movement, and involuntary motor movement. Most people get dreams during the REM stage.

Waking up due to dreams or nightmares is also more prevalent in the REM stage. According to an article published in the American Daily Physician, 80% of dreamers wake up from nightmares during the REM sleep or onset sleep.

What seems to be responsible for the profound responses to nightmares is the amygdala. The amygdala in the brain is associated with processing emotions. During the REM period of the night, the amygdala is highly active, which leads to intense emotional responses to nightmares. So when a person wakes up from a nightmare during the REM stage of sleep, their negative emotions are through the roof.

Dreamers that Encounter Nightmares Frequently

Even though anybody can have nightmares, some people are more susceptible to getting them. People with specific disabilities can have frequent nightmares related to their disability. For instance, a study published in 1990 in the journal Sleep Medicine reported that blind people are more prone to having dreams about getting into a car accident than people with vision. The fear of getting hit by a car or spilling coffee in a social gathering in blind people makes them four times more likely to have nightmares related to it.

Past trauma or distressing circumstances make certain people more vulnerable to the horrors of nightmares than others. A 1999 study published in the American Journal of Abnormal Psychology found that 40% of college students had at least one nightmare in a two-week study. These stats direct towards a strong connection between nightmares and everyday stress.

The only way to escape nightmares is to handle our fears of the day. Once a person learns to manage their everyday stresses properly, they will be less likely to have nightmares, unless they have a nightmare-inducing condition like a sleep disorder.