Obsessive–compulsive disorder, or OCD, is a type of mental health condition where someone has thoughts (or obsessions) that make them feel very worried or make it hard for them to do things. People with OCD also have certain behaviors (or compulsions) that they do in an effort to get rid of these thoughts and feel better. For example, someone with OCD might do something over and over, like wash their hands, check locks on doors, or count, as compulsions. These behaviors make them feel a little better but the thoughts still come back.