Last updated: October 2026
Intrusive thoughts are unwanted, upsetting thoughts, images or urges, often about harm, sex, illness or doing something out of character. Almost everyone has them, and having one doesn’t mean you want it or will act on it. They become a problem when they’re frequent and distressing, which can be a sign of anxiety or OCD.
Below: common examples, why they happen, when they might be OCD, how to stop them taking over, and where to get help.
Remember: a thought is not an action or a wish. The fact that a thought upsets you usually shows it goes against your values.
Examples of intrusive thoughts
The NHS notes that almost everyone has unpleasant or unwanted thoughts at some point, including sudden violent or offensive images. Studies of people without OCD have found the same kinds of thoughts are very common. Typical examples:
| Type | Example |
|---|---|
| Harm | “What if I pushed someone onto the train tracks?” or an image of hurting a loved one |
| Accidents | “What if I left the cooker on and the house burns down?” |
| Contamination | “What if I’ve caught something and pass it to my children?” |
| Health | “What if this headache is a brain tumour?” See health anxiety |
| Sexual | Unwanted sexual thoughts or images that feel shocking or wrong |
| Relationships | “What if I don’t really love my partner?” |
| Religion or morality | Blasphemous thoughts, or fear of being a bad person |
| New parents | Sudden images of the baby being harmed, which are very common after birth |
Why do intrusive thoughts happen?
Your brain produces thousands of thoughts a day, many random. Intrusive thoughts are part of that background noise. They tend to show up more when you’re:
- stressed or anxious. See stress symptoms and anxiety symptoms
- tired or short of sleep. See sleep deprivation
- going through a big change, such as becoming a parent
- experiencing hormonal changes. See PMS and perimenopause
- low in mood. See low mood vs depression
The thoughts that stick are usually the ones that clash most with what you care about. A loving parent gets thoughts about harming their child precisely because it horrifies them.
Intrusive thoughts and OCD
Obsessive compulsive disorder (OCD) has three parts, according to the NHS:
- Obsessions: unwanted, intrusive thoughts, images or urges that keep coming back.
- Emotions: intense anxiety or distress.
- Compulsions: repeated behaviours or mental acts to ease the anxiety, such as checking, washing, seeking reassurance, praying, counting or mentally “undoing” the thought.
The compulsion brings brief relief, but the anxiety returns and the cycle repeats. Some people have mostly mental compulsions, which is sometimes called “Pure O”. If intrusive thoughts and the things you do to neutralise them take up a lot of time or interfere with your life, it may be OCD. The good news is that OCD is very treatable. See how to stop overthinking.
Why fighting them makes them worse
Trying hard not to think something tends to make it come back more. Try not to think of a pink elephant for 30 seconds and you’ll see. When you treat an intrusive thought as dangerous, by arguing with it, checking or seeking reassurance, your brain learns it’s important and serves it up more often.
What helps is changing your relationship with the thought, not getting rid of it.
Intrusive thoughts after having a baby
Sudden, frightening thoughts or images of something bad happening to your baby are extremely common in new parents, both mums and dads. You might picture dropping the baby, them being hurt, or even yourself causing harm, and feel horrified. These thoughts are usually your brain’s over-protective alarm system working overtime, fuelled by exhaustion and the huge responsibility of a newborn.
- Having the thoughts doesn’t mean you’re a bad parent or a danger to your baby.
- Avoiding your baby, or things like bathing them, tends to make the fear stronger.
- Talk to your health visitor, midwife or GP. They hear this often and can offer support.
- If the thoughts are constant, or come with low mood or anxiety, it may be postnatal anxiety, depression or perinatal OCD, which are all treatable.
How to stop intrusive thoughts taking over
- Name it. “That’s an intrusive thought.” Labelling it creates distance.
- Don’t argue or analyse. Let it be there without trying to prove it wrong.
- Let it pass like a car going by. Notice it, then return to what you were doing. See mindfulness for beginners.
- Reduce reassurance-seeking and checking, a little at a time.
- Don’t avoid things because of the thought, such as knives or holding the baby. Avoidance keeps the fear going.
- Calm your body when anxiety spikes. See box breathing and grounding techniques.
- Look after the basics: sleep, exercise, less caffeine and alcohol. See does caffeine cause anxiety?
- Talk about it with someone you trust, or a professional. Saying it out loud often takes away its power.
A calming evening routine can help when thoughts feel louder at night. Our Magnesium Glycinate Sleep Complex is a caffeine-free bedtime drink with L-theanine, and magnesium contributes to normal psychological function. Some people take our Flow CBD Oil as part of their daily routine. CBD is a food supplement, not a treatment for OCD or anxiety. The FSA’s 10mg a day figure for CBD is precautionary advice rather than a legal limit, set while longer-term safety research continues. At Evopure we think it is a very cautious figure, and many adults use more. If you go above it, increase slowly, and check with your GP or pharmacist first if you take any medication. See anxiety at night.
When to get help
See a GP or refer yourself to NHS Talking Therapies if intrusive thoughts are frequent, distressing, take up a lot of your time or stop you doing things. The main treatment for OCD is CBT with exposure and response prevention (ERP), and sometimes medicine. OCD-UK also offers support. If you’re a new parent with distressing thoughts, tell your health visitor or GP. These thoughts are common and you won’t be judged.
If you’re having thoughts of harming yourself and feel you might act on them, that’s different. Call 999, NHS 111 or Samaritans on 116 123. See how to deal with anxiety.
FAQs
Are intrusive thoughts normal?
Yes. Almost everyone has unwanted, upsetting thoughts sometimes, including violent or sexual ones. Having them doesn’t mean you want them or will act on them.
How do I stop intrusive thoughts?
Don’t fight or analyse them. Label them as intrusive thoughts, let them pass, cut back on checking and reassurance, and look after sleep and stress.
Are intrusive thoughts a sign of OCD?
Not on their own. It may be OCD if the thoughts are frequent and distressing and you feel driven to do things, such as checking or seeking reassurance, to ease the anxiety.
Can anxiety cause intrusive thoughts?
Yes. Stress, anxiety, tiredness and hormonal changes can all make intrusive thoughts more frequent and harder to let go.
What is the treatment for intrusive thoughts?
Self-help can help with milder thoughts. For OCD, CBT with exposure and response prevention (ERP) is the main treatment, available through NHS Talking Therapies.
Sources
- NHS. Symptoms of obsessive compulsive disorder (OCD).
- Purdon C, Clark DA (1993). Obsessive intrusive thoughts in nonclinical subjects. Part I. Behaviour Research and Therapy.
- Julien D et al (2007). Intrusive thoughts, obsessions, and appraisals in obsessive-compulsive disorder: a critical review. Clinical Psychology Review.
- OCD-UK. ocduk.org.
This guide is general information, not medical advice. Evopure makes the Magnesium Glycinate Sleep Complex and Flow CBD Oil.
