One characteristic of Obsessive-Compulsive Disorder (OCD) is obsessions. Obsessions are defined as recurrent, persistent, intrusive thoughts, images or impulses that are distressing to the individual. Common obsessional themes are ideas (e.g. there are germs everywhere) or doubts (e.g. something important is overlooked). These thoughts, ideas or images are not simply excessive worries about everyday problems, they are seen as uncontrollable and the individual tries to suppress them. However, the individual may recognize that the thoughts are a product of their mind.
Another characteristic of OCD is compulsions. Compulsions are defined as repetitive behaviors or mental acts in response to obsessions. However, these acts are not connected in any realistic way to solving the obsessions. Other characteristics are that these obsessions and compulsions are time consuming and interfere with every day life.