# Contamination OCD: why washing never feels like enough and when it is a disorder > You wash your hands until they sting and the feeling of dirt will not go away. Why it happens, when it is contamination OCD and which test can help you find out. *https://mypsicotest.com/en/blog/contamination-ocd/ · Published: 2026-10-26 · 9 min read · MyPsicoTest team* You get home and head straight for the bathroom. You wash your hands counting to twenty as you scrub, rinse, and start again because you touched the tap. Your coat stays by the door, apart from everything else, because it has come in "from outside", and your phone gets a wipe before it goes on the table. When you finally sit down, your knuckles are red and cracked, and the feeling of dirt is still there. If this sounds familiar, it may be **contamination OCD**, sometimes called **cleaning OCD**, one of the most common forms of obsessive compulsive disorder. This guide explains what it is, how it differs from simply being a clean person, why washing never seems to be enough, which signs suggest a disorder, which treatment works and which test can guide you. ## What is contamination OCD? The [NHS](https://www.nhs.uk/mental-health/conditions/obsessive-compulsive-disorder-ocd/overview/) describes an **obsession** as an unwanted and unpleasant thought, image or urge that repeatedly enters your mind, causing feelings of anxiety, disgust or unease, and a **compulsion** as a repetitive behaviour or mental act that you feel you need to do to temporarily relieve those feelings. Among the common obsessions it lists fear of contamination by disease, infection or an unpleasant substance, and it gives an example: a person who fears contamination with germs may wash their hands repeatedly. Among the common compulsions it lists cleaning and hand washing, but also avoiding places and situations that could trigger obsessive thoughts. OCD symptoms tend to cluster. A [meta-analysis by Bloch and colleagues](https://pubmed.ncbi.nlm.nih.gov/18923068/), covering 21 studies and 5,124 participants, found four broad dimensions: symmetry, forbidden thoughts, hoarding and one of **cleaning and contamination**. In other words, fear of contamination and washing turn up together so consistently that they form a type of their own. In the US survey by Ruscio and colleagues, one in four people with OCD (25.7%) had contamination obsessions or compulsions. The fear may centre on germs, dirt, chemicals or the possibility of passing something on to other people. And it does not always come alone: many people have several forms of OCD at once. If you also check doors and appliances, we explain that in [Checking OCD: why you check again and again and when it becomes a disorder](https://mypsicotest.com/en/blog/checking-ocd/), and if what keeps coming back is images or ideas that frighten you, in [Intrusive thoughts: what they are, why they appear and when to worry](https://mypsicotest.com/en/blog/intrusive-thoughts/). ### Being a clean person is not the same as having OCD Plenty of people like a spotless home or wash their hands often, and that is not a disorder. The difference lies in why you clean and what it costs you. Rachman, who devoted a whole review to this fear, put it like this: compulsive cleaning is an attempt to remove a feeling of contamination that is experienced as a threat to physical health, mental health or social life. Someone who enjoys cleaning finishes and feels good. With OCD, you clean to calm fear or disgust, the relief does not last and the ritual has rules you cannot skip. The cost matters too. Diagnostic criteria refer to obsessions or compulsions that take up a lot of time, for example **more than an hour a day**, or that cause significant distress or interfere with work, study or relationships. ## Why washing never feels like enough The mechanism is the same as in other types of OCD. The NHS describes it as a cycle: the compulsion relieves the anxiety for a moment, but the obsession and the anxiety soon return and it all begins again. Each wash teaches you that washing was necessary, and the next fear arrives stronger. ### When you feel dirty without touching anything There is one detail that puzzles people who experience it. Rachman pointed out that the feeling of contamination can arise without any physical contact, and it is now called **mental contamination**. Coughtrey and colleagues interviewed 20 people with contamination OCD, and all of them described times when they had felt dirty or contaminated without touching anything dirty or dangerous. It was a diffuse, internal dirtiness that was not on their hands, and yet it brought an urge to wash in every case. It mainly had a human source: a person, or something that had happened with someone. In two later experiments by the same group, with volunteers who did not have OCD, recalling memories of betrayal, humiliation, harm or a moral violation was enough to increase that feeling, along with anxiety, the urge to wash and even actual washing. And when the memory was brought back and the person washed again and again, the feeling persisted. Water cannot reach a memory. ### The role of disgust The NHS includes disgust among the feelings an obsession can cause, and research links it particularly to contamination OCD. A meta-analysis by Mitchell and colleagues compared laboratory studies of learned disgust and learned fear and found that disgust was harder to extinguish. The study concludes that extinction-based approaches, such as exposure, may struggle more when disgust is the main emotion. ![Hand in a yellow rubber glove wiping a cupboard handle with a cloth, one of the surfaces cleaned over and over in contamination OCD](https://mypsicotest.com/assets/img/blog-limpiar-tirador-toc-de-contaminacion-1200.webp) ## Signs it may be contamination OCD - You wash your hands many times a day, for a long time or in a fixed order, and if you get it wrong you start again. - You follow a ritual when you get home: "outside" clothes kept apart, a long shower, your phone disinfected. - You avoid touching door handles, handrails, money or public toilets, or you touch them with a tissue or your sleeve. - You clean surfaces that are already clean or get through cleaning products at an unusual rate. - You ask the people you live with to wash or change when they come in, or not to sit on your bed in their outdoor clothes. - The skin on your hands is irritated or cracked. The NHS points out that contact dermatitis is most commonly caused by irritants such as soaps and detergents or regular contact with water. - You feel dirty after a memory or after being with someone, without having touched anything. - All this takes up more than an hour a day or limits you at work, in your studies or in your relationships. ## Is there a contamination OCD test? There is no **OCD test** just for contamination, but the [OCD Test](https://mypsicotest.com/en/ocd-test/) from MyPsicoTest covers its three parts. The obsession: "I worry about becoming contaminated or ill from touching objects, surfaces or people I consider dirty or dangerous". The ritual: "I wash my hands, shower or clean far more than necessary, or I do it following a fixed procedure I cannot deviate from". And the avoidance: "I avoid places, objects, people or situations that trigger unpleasant thoughts or that would force me to perform rituals". There are 16 statements about the last month, and for each one you mark how much that experience has bothered you, from "Not at all" to "Extremely"; it takes about five minutes. The score runs from 0 to 64, with four guidance levels (few indicators, mild symptoms, moderate indicators and high indicators), and it is broken down into three areas: obsessions and intrusive thoughts, compulsions and rituals, and time and interference. The last one asks, for example, whether the thoughts and rituals take up more than an hour a day. It is a screening tool, not a diagnosis. The result is calculated on your device and your answers are not stored. ### Other tests that may help If your main worry is that you already have a serious illness, rather than getting dirty or catching something, health anxiety may fit better, and the [Anxiety Test](https://mypsicotest.com/en/anxiety-test/) helps you gauge how much anxiety you are carrying. And because the NHS lists depression and generalised anxiety disorder among the problems that can come with OCD, if your mood has been low for weeks, try the [Depression Test](https://mypsicotest.com/en/depression-test/) as well. All the questionnaires, free and anonymous, are in the [psychological tests](https://mypsicotest.com/en/psychological-tests/) catalogue. ## Which treatment works for contamination OCD The NHS explains that therapy for OCD is usually **cognitive behavioural therapy** (CBT) with **exposure and response prevention** (ERP): facing your fears without neutralising them with compulsions, starting with the situations that cause the least anxiety. In contamination OCD, an exposure ladder might begin with leaving your outdoor coat on the sofa, move on to touching the TV remote without disinfecting it and end with using a public toilet and washing your hands only once. You work step by step, with exercises at home between sessions. The therapy has strong support. A [meta-analysis by Öst and colleagues](https://pubmed.ncbi.nlm.nih.gov/26117062/) pooled 37 trials of CBT for OCD and found very large effects compared with waiting lists and with placebo; CBT also did better than antidepressant medication. When the feeling of dirt comes from a memory or a person, therapy works on that source as well, because washing cannot reach it. And if disgust is the main emotion, it helps to know that it may take longer to ease and to talk about this with whoever is treating you. According to the NHS, people with fairly mild OCD usually need about 8 to 20 sessions; if medication is needed, an SSRI can take up to 12 weeks to make a difference. We explain what therapy involves and how to choose a professional in [Therapy for OCD: what treatment involves, how long it takes and how to choose](https://mypsicotest.com/en/blog/therapy-for-ocd/). ## What to do if you recognise yourself - **Do not feel ashamed.** The NHS stresses that OCD is a health condition like any other and that it is not your fault. - **Do not wait for it to pass.** The NHS also warns that OCD is unlikely to get better without proper treatment. - **Look after your skin in the meantime.** For contact dermatitis, the NHS advises applying emollients frequently and in large amounts and, if needed, using emollient soap substitutes. - **Talk to the people you live with.** If your family washes, changes or cleans to reassure you, therapy can help everyone stop doing so gradually. - **Ask for an assessment.** A good first step is to take the test and bring the result to your GP or a psychologist. At the end of the test you will find our recommendation of a licensed psychologist who works with OCD and anxiety, online too. ## Frequently asked questions ### What is contamination OCD? It is a form of obsessive compulsive disorder in which a person fears becoming contaminated, getting ill or passing something on to others, and washes or cleans again and again to calm down, although the relief does not last. It is also called cleaning OCD. ### How do I know if it is OCD or I just like things clean? By the reason and the cost. With OCD you clean to get rid of fear or disgust, you follow rigid rules and the relief is brief; it also takes up a lot of time, for example more than an hour a day, or interferes with your life. ### Why do I feel dirty when I have not touched anything? This is known as mental contamination. In a study of 20 people with contamination OCD, all of them had felt dirty without physical contact, often linked to another person, and felt an urge to wash. ### Can washing my hands so often damage my skin? It can. The NHS explains that contact dermatitis is mostly caused by irritants such as soaps and detergents or regular contact with water, and it recommends emollients. ### How is contamination OCD treated? With cognitive behavioural therapy with exposure and response prevention, which means gradually approaching what you fear without washing or cleaning afterwards. If OCD is more severe, an SSRI antidepressant can be added. ### How many sessions does it take? According to the NHS, people with fairly mild OCD usually need about 8 to 20 sessions, with exercises at home. If it is more severe, treatment may take longer. ### Is there a test to find out if I have contamination OCD? There is no test just for contamination, but the MyPsicoTest OCD test includes statements about fear of contamination, excessive washing and cleaning, and avoidance, and gives a result broken down by area.