Obsessive-compulsive disorder (OCD) is a type of mental illness that affects one's behavior and thinking.

Obsessive-compulsive disorder (OCD) is a chronic disease of the nervous system and is a common psychological problem associated with anxiety in which a person has unwanted and uncontrollable thoughts, reoccurring ideas, excessive sensations, (obsessions) that make him feel motivated to do something repeatedly (compulsions).

OCD is characterized by both obsessive and compulsive symptoms.