It is a disorder characterized by unwanted repeated thoughts, ideas or images (obsessions) which cause distress and anxiety and to get relieved of that anxiety a person feels driven to do certain actions repeatedly (compulsions).

Examples of Obsessions : Excessive concern about cleanliness and. symmetry, unwanted sexual and blasphemous thoughts.

Examples of Compulsions : and cleaning repeatedly and ina ritualized manner repeated checking behaviour, repeatedly counting/reading/praying ete

Treatment: The two main types of treatment for OCD are Psychotherapy and Medicines. Usually, a combination of medicines and psychotherapy is advised

Psychotherapy :

Cognitive behaviour therapy(CBT) is very effective in OCD. Exposure and response prevention (ERP) involves gradually exposing a person to anxiety-provoking situations and things and encouraging them to face your anxiety without neutralizing them with compulsions.

Medicines :

Antidepressants, mainly SSRIs are the most commonly prescribed medicines for OCD.
For more information see this information booklet on OCD (courtesy-NIMHANS).