Obsessive compulsive disorder (OCD Home A-Z Health Information Health Library A-Z Obsessive Compulsive Disorder (OCD Overview Obsessive compulsive disorder (OCD) consists of two key components: obsession and compulsions. Obsessions are recurrent, persistent, and anxiety-provoking and intrusive, unwanted thoughts, urges or images. Compulsions, on the other hand, are repetitive behaviours or rituals performed in response to these obsessions to alleviate anxiety and distress. Common obsessions include fear of contamination, which is usually accompanied by compulsive hand washing. Causes and risk factors The exact cause is unknown. Some risk factors include:GeneticsChildhood traumaBrain structure Symptoms Fear of contaminationFear of misplacing thingsDesire to look appealing Diagnosis OCD is diagnosed throughPhysical examinationPsychiatric evaluation. Treatment PsychotherapyMedicationsDeep brain stimulation