Night terrors can be a frightening sleep problem — whether you experience them or you see a partner suffering from them. But what exactly are they?
Night terrors tend to happen in a sleep stage known as deep sleep, rather than when in REM, which is when nightmares happen. They often mean that the person experiencing them will shake, scream and move erratically in their sleep while not even being aware it’s happening.
Children are more likely to experience night terrors, and normally grow out of them, but adults can also experience them.
Like any sleep condition, some lifestyle factors, such as stress or lack of sleep can exacerbate the condition, so knowing how to prevent them and when you should consult a doctor is paramount.
For Sleep Awareness Week 2025, we dive into the research and ask sleep expert and clinical psychologist Dr Leah Kaylor what causes night terrors, how to prevent them and ways to cure your night terrors for a peaceful slumber.
What are night terrors?
You may have experienced nightmares, where you wake up, possibly sweating and shaking as you’ve remembered an awful dream, but night terrors can be completely different.
So, what exactly are they? “Night terrors are episodes of intense fear, screaming, and physical movement that occur during deep sleep,” explains sleep expert Dr Leah Kaylor.
Night terrors are episodes of intense fear, screaming, and physical movement that occur during deep sleep
Dr Leah Kaylor
“Unlike nightmares, people who experience night terrors typically have no memory of the event upon waking.”
Although only around 2-4% of the population experience them, she goes on to add that night terrors occur because of overactivation of the central nervous system during deep sleep.
“They happen when the brain struggles to transition between sleep stages, causing a person to become “stuck” in between wakefulness and deep sleep.”
What causes night terrors?
Some common triggers for night terrors include sleep deprivation, stress, anxiety, fever, illness, medications, alcohol, or other underlying sleep disorders. Here we look at some of them in more detail.
1. Stress
While research shows that night terrors in children can be blamed on emotional trauma, there is little research that shows why adults suffer from them. However, Dr Kaylor explains why stress can be one of the causes.
“Stress makes the brain go into fight or flight mode making the brain more likely to misfire during sleep transitions, leading to night terrors.”
She adds that stress increases cortisol, disrupting sleep cycles and increasing fragmentation in sleep patterns: “This makes the brain more vulnerable to sudden awakenings and sleep disturbances.”
2. Sleep deprivation
If you are surviving on around 5-6 hours, or less a night, this could also affect how you sleep.
This is because sleep deprivation causes a “rebound effect, where the brain compensates by increasing deep sleep,” the sleep expert explains. “This intensifies sleep instability, making sudden awakenings more likely.”
This is down to your brain being overtired. “This in turn makes it struggle to maintain smooth sleep transitions, causing a person to wake up partially during deep sleep—this incomplete awakening results in a night terror episode.”
3. Sleep disruption
If you are sleeping in a noisy environment, or you’re likely to have your sleep disrupted by a snoring or restless partner, it could signal to the brain that you’re not in a safe place to sleep.
This disruption to your sleep can interrupt your deep sleep processes, leading to an onset of night terrors.
4. Sleep disorders
If you’ve already been diagnosed with a sleep disorder this could bring on night terrors.
“Sleep apnea causes breathing interruptions that lead to frequent partial awakenings which can trigger night terrors,” Dr Kaylor explains, “while restless leg syndrome causes discomfort, making sleep fragmented and unstable.”
She adds that insomnia leads to sleep deprivation which increases the likelihood of deep sleep disturbances.
5. Genetics
Studies show that night terrors and sleep disorders can be hereditary, as they can be linked, especially in children, to genetic traits affecting how the brain transitions between sleep stages.
Experts believe that genes influencing brain activity and arousal responses during deep sleep may contribute.
While others may inherit a heightened sensitivity in the central nervous system, making them more likely to wake up when asleep.
What’s the difference between nightmares and night terrors?
Nightmares and night terrors not only differ in their symptoms, but also when they happen. When we sleep we go through different sleep stages, from light, to deep and then to REM.
Dr Kaylor explains that terrors happen during deep sleep. This is when the brain is in its deepest, most restorative state but still retains some ability to process stimuli.
What is REM sleep?
REM sleep refers to a stage of sleep that is characterized by rapid eye movement. It’s when most people experience dreams and it’s responsible for emotional processing and memory consolidation.
So, how will someone react to night terrors? “While they may look very scared, act panicked, or scream as well as physically act out (e.g. sitting up, thrashing) the person has no memory upon waking,” explains Dr Kaylor, “despite efforts to calm them, the person is usually unresponsive.”
Nightmares are different as they happen in REM (Rapid Eye Movement) sleep – the stage where your brain is more active, and your brain has vivid dreams.
“Nightmares are also remembered, and normally accompanied by anxiety and fear,” explains the sleep doctor, adding that, “nightmares occur more frequently in adults, while night terrors are associated with children.”
How to prevent night terrors
It can be difficult to know how to prevent night terrors without understanding the root cause. However, there are certain lifestyle changes you can make that decrease the likelihood of experiencing night terrors.
Get enough quality sleep
Kaylor says that prioritizing healthy sleep is key to avoiding the dreaded night terrors. After all, quality sleep is more important than the quantity you get.
“Try to get 7-9 hours per night and stay consistent with your wake and sleep times.” She also advises that you should try to avoid naps.
Relax before bed
When you’ve had a busy day, physically or mentally it can subconsciously creep into bedtime or our sleep patterns.
If you know you’ve had a stressful or emotionally draining day make sure you take time to relax before you go to bed.
Download a mediation app such as Headspace, or journal down your thoughts as part of a calming nighttime routine.
Address the root cause
Of course the night terrors could be caused by an underlying issue, such as a sleep disorder.
If your child doesn’t grow out of them or you’re an adult and it’s affecting your health, Dr Kaylor advises you to: “Consult with a health professional to address any underlying sleep disorders that may be contributing to the night terrors.”
Tom’s Guide created this content as part of a paid partnership with Helix Sleep. The contents of this article are independent and solely reflect the editorial opinion of Tom’s Guide.
