Obsessive-compulsive disorder (OCD) is a disorder in which people suffer from unwanted and disturbing thoughts over and over again. Obsessions are unwanted recurrent and persistent thoughts and impulses experienced at some time during the disturbance. These thoughts and impulses are not about major issues and life's problems but rather irrelevant details. They are disturbing and inappropriate and cause marked anxiety or distress. The person with this disorder attempts to ignore the thoughts and suppress or neutralize them with some other thought or action. The person realizes that the obsessive thoughts and images are a product of his or her own mind but are powerless to stop them. Compulsions are repetitive behaviors such as hand washing, ordering, or checking. They could also include mental acts like praying, counting, and repeating words. These are aimed at preventing or reducing distress and preventing the dreaded situation. The person feels compelled to perform the compulsion to relieve anxiety from the obsession. They often have very rigid rules about how the compulsions should be performed. .
Common obsessions include: contamination, fear of germs, imagining that one has harmed his or herself or others, imagining losing control of aggressive urges, excessive religious or moral doubt, forbidden thoughts, a need to have things "just so", and a need to ask, tell, and confess. Common compulsions include excessive washing, repeating, checking, touching, counting, ordering, arranging, hoarding, and praying. Many people may think they can identify with some of the obsessive compulsive disorder symptoms, like checking door locks, or double checking stoves or heaters but this is completely normal. Compulsive behaviors are performed with the goal of preventing or reducing distress or preventing some dreaded situation but they are not realistically connected with what they are designed to neutralize and they are clearly obsessive.