Obsessive compulsive disorder (OCD) is an anxiety disorder, characterised by the presence of recurring intrusive and unwanted thoughts, images, or impulses – obsessions and repetitive behavioural and mental rituals – compulsions.
People with OCD are usually aware that their symptoms are irrational and excessive, but they find the obsessions uncontrollable and the compulsions difficult or impossible to resist.
The causes are not fully understood. It is likely that each person's OCD is the result of several interacting factors, including genetic vulnerability, stressful life events, hormonal changes, and personality traits.