Last updated: October 2026
Nightmares are vivid, upsetting dreams that wake you up. Most adults have them sometimes. Common triggers are stress, anxiety, poor sleep, alcohol, late meals, some medicines and past trauma. To have fewer, keep regular sleep times, wind down before bed, cut alcohol and talk through worries. If they’re frequent, imagery rehearsal therapy works well.
Below: what causes nightmares, how to stop them, what to do after one, nightmares vs night terrors, and when to see a GP.
What causes nightmares?
| Cause | Why |
|---|---|
| Stress and anxiety | Daytime worries often show up in dreams. See stress symptoms |
| Poor or broken sleep | Being overtired can lead to more intense dreaming |
| Alcohol | It disrupts sleep, and dreams can rebound later in the night |
| Late, heavy meals | Can make you more likely to wake |
| Medicines | Some antidepressants, blood pressure medicines and others. Don’t stop a medicine without talking to your GP |
| Stopping some substances | Coming off alcohol, cannabis or some sleeping tablets can cause vivid dreams for a while |
| Trauma | Repeated nightmares about a frightening event can be a sign of PTSD |
| Fever or illness | Can cause strange, vivid dreams |
How to stop having nightmares
- Keep regular sleep and wake times. See how to sleep better.
- Wind down for an hour with dim lights and no screens.
- Avoid scary or stressful content before bed: news, horror films, work emails.
- Cut back on alcohol, especially in the evening.
- Eat your evening meal 2 to 3 hours before bed.
- Write down worries before bed. See journal prompts for anxiety.
- Try a relaxation technique in bed. See box breathing.
- Talk about recurring dreams with someone you trust.
Imagery rehearsal therapy
For frequent nightmares, the American Academy of Sleep Medicine recommends imagery rehearsal therapy. You write down a recurring nightmare, change the story to something less frightening, then rehearse the new version in your mind for a few minutes each day. Over a few weeks, many people find their nightmares become less frequent and less upsetting. A therapist can guide you through it.
What to do after a nightmare
- Remind yourself it was a dream and you’re safe.
- Breathe slowly with a longer out-breath.
- Ground yourself: notice the bed, the room, the sounds. See grounding techniques.
- Turn on a dim light and sip some water.
- If you can’t settle after 20 minutes, get up and do something calm before going back to bed.
Many people find a calm evening routine helps them settle. Magnesium contributes to normal psychological function. Our Magnesium Glycinate Sleep Complex is a bedtime drink, and our Reishi Mushroom Adaptogenic Complex is a cosy hot chocolate. See best tea for sleep.
Nightmares vs night terrors
| Nightmares | Night terrors | |
|---|---|---|
| When | Usually later in the night, in dream sleep | Usually in the first few hours of sleep |
| Waking | You wake up and remember the dream | The person often doesn’t fully wake and doesn’t remember it |
| Who | Common at any age | Mostly children |
Also see sleep paralysis and hypnic jerks.
When to see a GP
See a GP if nightmares happen often, stop you sleeping, leave you scared to go to bed, affect your daytime, started with a new medicine, or are linked to a traumatic event. Talking therapies can help with both nightmares and the anxiety behind them.
FAQs
Why do I keep having nightmares?
Common causes are stress, anxiety, poor sleep, alcohol, some medicines and past trauma. See a GP if they’re frequent or distressing.
How can I stop having nightmares?
Keep regular sleep times, wind down before bed, avoid alcohol and scary content late at night, and write down worries. For frequent nightmares, imagery rehearsal therapy helps.
What should I do after a nightmare?
Remind yourself you’re safe, breathe slowly, turn on a dim light and sip water. Get up for a while if you can’t settle.
Can stress cause nightmares?
Yes. Stress and anxiety are among the most common triggers for bad dreams.
What is the difference between nightmares and night terrors?
You wake from a nightmare and remember it. During a night terror, the person often stays half asleep and doesn’t remember it.
Sources
- Morgenthaler TI et al (2018). Position paper for the treatment of nightmare disorder in adults: an American Academy of Sleep Medicine position paper. Journal of Clinical Sleep Medicine.
- NHS. Night terrors and nightmares.
- NHS. Post-traumatic stress disorder (PTSD).
This guide is general information, not medical advice. Evopure makes the Magnesium Glycinate Sleep Complex and Reishi Mushroom Adaptogenic Complex. We don’t recommend our products during pregnancy or breastfeeding.
