Trauma, Nightmares and How to Sleep Better Again

Have you ever woken from a dream where you were being chased by something you couldn’t quite escape from, something horrible happened to someone you love, or you suddenly realised you had an exam you’d completely forgotten to study for?

Perhaps you’ve dreamed that you’re falling, or trying to scream but no sound comes out. Or maybe you’ve woken with your heart racing after a nightmare that made perfect sense while you were asleep, but sounds bizarre the moment you try to explain it.

Whilst unpleasant, experiencing the occasional nightmare is an ordinary part of dreaming. But some people, especially those who have experienced trauma, can struggle with nightmares more regularly. When this happens, they can start to affect your sleep and quality of life.

So, why do nightmares happen? And what can help?

What Is a Nightmare?

A nightmare is a distressing, vivid dream. Contrary to common understanding, nightmares are also not just about fear. They can involve other emotions such as sadness, anger, shame, grief or disgust. Nightmares happen during REM sleep, the stage most strongly associated with vivid dreaming, which is why we can often remember at least some of what happened when we wake up. Nightmares are very common in childhood, but most adults have the occasional nightmare as well.

Nightmares are different from night terrors. A nightmare is a frightening dream that you wake from and at least partially remember. A night terror happens during deep non-REM sleep and is an experience of partial awakening, rather than a dream that you wake from. Someone may scream, sit upright, sweat or appear extremely frightened while remaining partly asleep, and often has little or no memory of it the next morning.

What Causes Nightmares?

Nightmares can be caused by a range of factors. They are more likely when sleep is disrupted or our sleep schedule changes, and have been associated with certain medications, alcohol and other substances.

Whilst there isn’t one universally accepted set of nightmare “types”, understanding a few broad categories can be useful for understanding why your nightmares might be happening:

Occasional Nightmares

These are the frightening dreams most of us experience from time to time. There is more likely to be an obvious cause. For example:

• You watch a horror film before bed and spend the night being pursued through an abandoned house.
• You’re part of an uncomfortable conversation at work and later dream about being criticised in front of everyone.
• It’s a hot summer’s night and you spend a restless evening tangled in sheets, dreaming of being restrained or trapped.

Occasional nightmares are just that, occasional, and tend not to recur or linger once the cause has been moved past.

Stress-Related Nightmares

These may appear or become more frequent during periods of stress, conflict, uncertainty, or significant life change. The dream may not reflect literally what is happening, but the emotions can feel familiar. A dream about sitting an exam you haven’t studied for, for example, might feel particularly fitting when you recognise you’re stressed or under pressure. Or a dream where you can’t find something important to you, like a pet or car, might make sense in the context of grief.

Trauma-Related Nightmares

However, one of the biggest causes of nightmares is trauma. Nightmares are one of the most common symptoms that can occur after experiencing a traumatic event, and often form part of Post-Traumatic Stress Disorder (PTSD). For some people, the dream closely resembles what happened; for others, the story line is different but carries a similar sense of danger, loss of control or vulnerability.

Because trauma memories can remain closely linked with the body’s threat response, these nightmares can feel especially vivid and emotionally intense, even after the person wakes up.

Trauma-related nightmares are also more likely to become recurrent. That is, they return repeatedly, or have a similar recurrent theme.

Why Does Trauma Show Up In Nightmares?

To answer this, it’s helpful to understand how memory and our waking experiences are processed.

Researchers believe nightmares can occur as part of the way our brain processes memory (in fact, this is part of what underpins the evidence-based treatment Eye Movement Desensitisation Reprocessing therapy, or EMDR).

Our brain has a natural, built-in way of processing our experiences so they can be stored in long-term memory and help us learn from what happened. It is proposed that REM sleep is a big part of this memory processing system. During REM sleep, the theory goes that the brain works through the experiences of the day, integrating what is useful for us to learn into long-term memory. Then we slowly forget the minute details we don’t need to hold onto.

Trauma Interrupts Natural Memory Processing Systems

When we experience something intensely distressing however, the brain can struggle to process the experience – think of a set of cogs that normally whir away smoothly, but then if they’re running too fast, they jam. This metaphorical ‘jamming’ of the gears means that the memory doesn’t fully integrate.

When the memories we are working through during REM sleep are distressing or traumatic, this can lead to nightmares in part because the brain is trying to process information that is distressing. Then, if our metaphorical gears are jamming on top of this, the distressing memory is also not being integrated.

Failure to integrate a traumatic memory means that it remains raw and visceral – when we think about what happened, the distress associated with the experience hits us with full force. This can explain the distress on waking from a trauma-related nightmare.

Encountering a trauma trigger in your day to day life can then kickstart the brain’s attempt to process the memory again, leading to a nightmare. Nightmares themselves can also become triggers, leading to a vicious cycle.

What To Do After Waking From a Nightmare

When you wake from a nightmare, you may know logically that you were dreaming while your body is still behaving as though something dangerous is happening.

This is where strategies drawn from Dialectical Behaviour Therapy (DBT) and other grounding approaches can be useful. Rather than immediately analysing the dream, the first task is helping your brain and body recognise: I’m awake, I’m here and safe, and the nightmare has ended.

You might work through the following steps:

1. Orient yourself to the present. Look around the room and name where you are, what day it is and a few familiar things you can see. Remind yourself: “That was a dream. I’m awake now.”
2. Reconnect with your senses. Feel the mattress beneath you, notice the temperature of the room, hold something cool or take a sip of water. Sensory information can help anchor you in what is actually happening right now.
3. Settle your breathing and body. Allow your breathing to become slower and more regular. Try using progressive muscle relaxation: you might unclench your jaw, lower your shoulders or deliberately relax muscles that feel tense.
4. Change your physical state if you need to. If you’re still highly alert, sitting up, turning on a soft light or getting out of bed for a short period can help break the feeling that you’re still caught in the dream.
5. Do something familiar and calming. Practice self-soothing: read something neutral, listen to calming audio or repeat a grounding exercise until you begin to feel sleepy again.

Try not to put pressure on yourself to fall asleep again immediately. The goal is first to help your nervous system recognise that the threat has passed. Sleep can follow.

What To Do During the Day to Reduce Nightmares

In addition to having a plan for when you wake from a nightmare, there are some other general tips that can be helpful:

• Practise grounding skills during the day, and before going to bed as part of your bedtime routine. This reduces your distress level across the course of the day, which makes nightmares less likely.
• Write yourself a checklist of what practical grounding steps to do when you have a nightmare, and reassuring statements you can say to yourself, that you can keep by the bed and read when you wake up. That way you’ll be well-prepared if you do have a bad dream.
• Avoid alcohol and caffeine in the evening. Caffeine makes it harder to relax, and alcohol can suppress REM sleep, causing a rebound effect in the latter part of the night. Both effects can worsen nightmares.
• It sounds obvious, but try to avoid upsetting or stressful content before bed. This means no doomscrolling, checking the news, or watching intense dramas or horror shows!
• Practice good sleep hygiene. For example, have a consistent sleep routine, and a soothing bedroom set up.

When to Get Support for Nightmares

An occasional nightmare is very common. But if nightmares are happening frequently, becoming increasingly distressing, disrupting your sleep or leaving you anxious about going to bed, it may be worth seeking some extra support. The same applies if they are affecting your mood, energy or concentration during the day, or seem connected with traumatic experiences or memories.

What helps will depend on what is contributing to the nightmares.

For recurring nightmares, one option is nightmare rescripting. DBT includes a rescripting-based skill called the Nightmare Protocol, which involves changing elements of a recurring nightmare and rehearsing the new version while awake. A psychologist with expertise in sleep can help you use this approach in a way that feels manageable, particularly if the nightmares are intense or longstanding.

If nightmares are connected with trauma, treatment may also involve working with the memories underlying the dreams. This could include trauma-focussed therapies such as Cognitive Processing Therapy, Schema Therapy, Internal Family Systems therapy, or EMDR. As those traumatic memories become less emotionally intense, trauma-related nightmares are also likely to reduce in time.

Because persistent nightmares can occur alongside stress, anxiety, trauma, medications, sleep difficulties and other health concerns, a GP or psychologist can also help you understand what may be contributing to them and work out which kind of support is most likely to help.

Sleep Can Feel Safe Again

Trauma-related nightmares can make sleep feel unpredictable, especially when you wake with your body reacting as though the danger is happening all over again.

But these responses can change. Grounding can help your nervous system reconnect with the present after a nightmare, while trauma-focused treatment can help address the distressing memories and threat responses that may be contributing to them.

You may not be able to control exactly what you dream about, but with time and the right support, those dreams can become less distressing, and sleep can begin to feel safer again.

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If you’d like to learn more about nightmares, you might enjoy reading Into the Dream Lab by sleep scientist Michelle Carr, or listen to Michelle explain dreams and nightmares in this podcast. You might also want to learn a quick but effective relaxation technique for sleep.