Nightmare fuel? Here's how (and why) scary movies affect your sleep

woman looking frightened, watching something on a laptop screen in bed
(Image credit: Getty)

Halloween is a time for frightening yourself silly with horror movies. If you don't have a natural disposition towards scary stuff, if just a glance at our best horror movies on Netflix list fills you with dread, that can quickly translate into nightmares or difficulty sleeping. We spoke to a sleep expert to find out exactly why that is, and how to avoid a night staring warily at the shadows in the corner of your room. 

According to qualified Sleep Scientist Theresa Schnorbach, there's no definitive reason why we have nightmares, although there are plenty of theories. "The purpose of dreaming is highly debated. Some researchers believe that dreams are a way for us to process our memories and help us understand our emotions," she explains. Based on that understanding, nightmares might be a way for us to make sense of events and experiences that have frightened us. 

"Most experts believe nightmares are caused by everyday stress and trauma," she continues. "Given the intense stimulus one gets from horror movies, especially when watched at night prior to bedtime, the brain could perceive this as a form of virtual reality, evoking typical stressful situations of real life."

How can horror movies affect sleep?

Theresa explains that most dreaming takes place during REM (rapid eye movement) sleep, which typically kicks in about 90 minutes into the sleep cycle and repeats every 90 minutes. "Intense, emotion-evoking dreams tend to be more memorable. Most of the time, when you wake up from a nightmare you can clearly recall the details of the dream, and in turn, may have difficulty falling back asleep."

woman lying in bed with her hands over her face

(Image credit: Getty)

How can you avoid a sleepless night after a horror movie?

Let's say you're not a natural horror aficionado, but you still want to get involved with the Halloween film fright-fest. Is there a way to hack the system and avoid the nightmares? According to Theresa, there's no definitive way to guarantee a nightmare-free night, but there are things you can do to help. 

"Working on your sleep hygiene and habits can help you build a better routine that is beneficial for getting a good night’s sleep, which may make any nightmares you have less bothersome," says Theresa, who works with Emma (the bed brand behind the Emma Original, one of the best mattresses around, based on our testing). Here are her top tips for a good night's sleep after a scary movie:

#1. Buddy up
"Try and find somebody to watch the film with, even better somebody who has seen the film before. Having someone else who knows what's coming can be very comforting when watching something scary."

#2. Avoid the bedroom
"I would advise against watching horror films in the bedroom, as watching horror is associated with experiencing a traumatic event. Associating one's bedroom with a traumatic event can be very problematic and dangerous for your sleep."

#3. Put down the coffee
"As much as we all like that afternoon cup of coffee, it isn’t always a good idea. Caffeine is a stimulant and can keep your mind awake when it should be slowing down."

#4. Distract yourself
"Talk to other people about other topics completely unrelated to the horror movie."

#5. Leave a light on
"Sleep gadgets such as sunrise alarms can help those who feel that light makes them feel safer. These alarms allow you to set times when the lights will switch on and off, thus avoiding night disturbances."

#6. Wind down
"As part of your evening routine, you should do activities that help feel calm and relaxed. Try some breathing exercises or having a bath to help you unwind before going to bed, and that may help improve your sleep."

What if that doesn't help?

If you've tried all of the above and still struggle to sleep after a horror movie, you might need to concede defeat. "If you are a person who isn’t sensitive to horror movies, then it’s likely you won’t have any problems with your sleep or nightmares. On the other hand, if you are more sensitive to the horror genre, then my advice is to try and avoid them altogether," says Theresa. 

If the nightmares are affecting your day-to-day life, it's not worth it – recognize that perhaps horror just isn't a genre for you. And if you're struggling with nightmares on a regular basis, you should see a doctor to figure out if there's another underlying cause, advises Theresa. 

You would perhaps be best off avoiding scary movies if you're feeling particularly unsettled at the moment, too. "Recent research from Emma found almost half (44%) of Brits are feeling more anxious," adds Theresa. "When you might already be feeling worried or anxious, a scary movie can play on these feelings so I would advise against watching if this is the case."

Theresa Schnorbach
Theresa Schnorbach

Theresa Schnorbach is a psychologist and sleep scientist, specialized in Clinical Psychology and Cognitive Neuropsychology. She has completed post-graduate training in Cognitive Behavioural Therapy for Insomnia (CBT-I) with the German Sleep Society (DGSM), endorsed by the European Research Society. She works as a sleep specialist for bed brand Emma.

Ruth Hamilton
Homes Editor, TechRadar

Ruth is currently Homes Editor on Tom's Guide's sister site TechRadar, where she reviews and writes about everything from air fryers to vacuum cleaners to coffee machines, as well as the latest smart home gadgets. Prior to making the shift to Homes, Ruth was Tom's Guide's Sleep Editor. A certified Sleep Science Coach, she has tested more mattresses than her small flat can handle and will talk at length about them to anyone who shows even a passing interest.

Read more
A young blonde woman watches tv in bed before she goes to sleep
Is watching TV in bed that bad for your sleep? Here's what the experts say
Woman lying awake in bed at night
Can’t sleep after a nightmare? Here are 5 tricks that work for me
A woman lying in bed after waking from a night terror with her hands over her eyes, scared
I asked a parasomnias expert what was causing my night terrors – her answer surprised me
A woman laying awake at night with arms overhead as she is waking up every hour
3 reasons you're waking up every hour at night — and how to stop it
A woman with dark hair lies in bed yawning because she is so tired and ready to sleep
Keep waking up at night? Fall back asleep fast with this 5-second pillow trick
A blonde woman wearing a blue t-shirt and pink eye mask on her forehead with messy bun sitting in bed as she stretches her arms overhead, waking up early to join the 5am club
The Sunday Scaries kept me awake at night — until these 5 sleep hacks helped me relax
Latest in Sleep
An older woman and man holding a kettlebell in their chest as they squat down in gym class
This workout could reduce insomnia among over 60s, says new study
A woman with dark hair lies in bed yawning because she is so tired and ready to sleep
Still tired after a full night’s sleep? A new study claims to know the reason why you’re always exhausted
Elon Musk at an event with his hands raised in the air, wearing a cap and reflective sunglasses
No, you shouldn’t follow Elon Musk’s sleep habits — here’s why
A woman in bed sleeping next to Momcozy Sunrise Sound Machine Wake-Up Light
The Momcozy Sunrise Sound Machine can make your night feeds and early mornings calmer — and it's just $40
Woman in bed sleeping
I keep my sleep score in the 90s thanks to this one easy habit
Woman drinking a glass of wine in a white bed wearing pajamas in a dim lit room
Using alcohol for sleep doesn't work — experts explain why and which drinks are worse than others for your sleep
Latest in Features
A young woman eats chocolate before bed
I discovered the best trivia about my favorite snacks using Gemini deep research — here’s what I learned
Google TV Streamer in front of TV
3 reasons to still buy a streaming device in 2025 — yes, even with smart TVs
Snap Grip Wallet.
I’ve tried dozens of wallet cases, but this MagSafe wallet does one thing I haven’t seen before
a woman's abs
Forget sit-ups — build core strength and boost your mobility in just 15 minutes with this Pilates routine
Samsung Galaxy S25 Ultra astrophotography.
I tried astrophotography on my Galaxy S25 Ultra and I’m not impressed — here’s why
a person wearing air compression boots
I’ve been using compression boots on my legs for a month — and they made a bigger difference than I expected