A person experiences intrusive, unwelcome thoughts (called obsessions) that are so persistent and upsetting that he or she fears the thoughts might not stop. In response, he or she tries to stop having those thoughts with a variety of efforts (called compulsions). Unfortunately, the compulsions usually become a severe, upsetting problem in themselves. For example, a man may have obsessive thoughts that he could pass swine flu on to his children, even though he doesn’t have the flu himself, and subsequently washes his hands repetitively in an effort to get rid of that thought. Or a woman may have obsessive thoughts that she left the garage door open, and repeatedly checks on it all night in an effort to stop thinking that thought. Not only do these efforts fail to rid the person of the unwelcome thoughts, but they become a new form of torment in that person’s life.