Obsessive-compulsive disorder (OCD) is an anxiety disorder in which a person becomes trapped in a pattern of intrusive and unwanted thoughts and repeatedly performs tasks or rituals to get rid of the thoughts. Fear of contamination is one of the most common obsessions, and handwashing and checking that something has been done are the most common compulsions.

• Obsessions are thoughts and worries that will not go away. These thoughts are usually irrational and cause anxiety. For instance, the person may constantly worry, “My hands are dirty. I will get a disease.” Obsessions usually lead to irrational behaviours (compulsions).
• Compulsions are recurring behaviours that a person feels a strong urge to do in response to obsessive thoughts or worries. For example, a person who has an obsession with dirty hands and disease may wash his or her hands over and over again.

In a person with obsessive-compulsive disorder, attempts to control his or her obsessions and resist the urge to perform certain compulsive behaviours may cause extreme anxiety or panic attacks.

Treatment includes medicines and counselling.