Obsessive–compulsive disorder (OCD) is a prevalent mental health condition characterised by persistent, intrusive thoughts (obsessions) and repetitive behaviours or mental acts (compulsions) aimed at alleviating anxiety. Individuals with OCD often find themselves trapped in a distressing cycle, as compulsions provide only temporary relief, perpetuating the need for repetition. OCD manifests in diverse forms, such as checking, counting or washing rituals, and its severity can range from mild to debilitating. Despite widespread misconceptions, OCD extends beyond a mere desire for order and cleanliness, impacting various aspects of daily life. Genetic, neurological, and environmental factors contribute to its development, and it often emerges in adolescence or early adulthood. In this episode, Dr Roger Henderson provides an overview of OCD, what we should be looking for to help identify patients with this condition, along with guidelines on effective treatments including cognitive behavioural therapy (CBT) and medication.