Obsessive-compulsive disorder (OCD) is a mental disorder in which people experience unwanted and repeated thoughts, feelings, images, or sensations (obsessions) and engage in behaviors or mental acts (compulsions) in response. Often a person with OCD carries out the compulsions to temporarily eliminate or reduce the impact of obsessions, and not performing them causes distress. OCD varies in severity, but if left untreated, it can limit one's ability to function at work, school, or home.
OCD is estimated to affect more than 2 percent of U.S. adults at some point in their lives, and the problem can be accompanied by other conditions, including anxiety disorders, depression, and eating disorders. It typically first appears in childhood, adolescence, or early adulthood.