Intrusive thoughts are a common experience, but for individuals with Obsessive-Compulsive Disorder (OCD), these thoughts can be overwhelming and distressing. One subtype of OCD, known as Purely Obsessional OCD (Pure O), primarily involves obsessive thoughts rather than visible compulsions. This article explores intrusive thoughts, the characteristics of Pure O, its symptoms, causes, psychological and physiological effects, and non-medication-based management strategies.