OCD was once considered an anxiety disorder, but since the new Diagnostic Statistic Manual (DSM-V) has been published (May 2013), OCD was incorporated into a category called "Obsessive-Compulsive and Related Disorders". OCD is characterized by the presence of frightening or disturbing intrusive, unwanted thoughts or images, nonsense words or even music (obsessions), and/or repetitive or stylized behaviors and/or thoughts designed to reduce the anxiety from the obsessions (compulsions). Both situations are usually recognized by the individual as irrational (except sometimes in children), and are usually ego-dystonic (thoughts/behaviors that do not fit with one's sense of self). In fact, people are often so scared or ashamed of having these thoughts that they don't admit them to their doctors and suffer in silence for an average of 14-17 years before getting effective treatment.
Obsessions are intrusive thoughts that create anxiety and/or distress and usually demand that something be done to reduce that feeling. (Fears in all examples listed below can also be represented by other feelings such as disgust or uncertainty)
Some examples of obsessions include:
Additionally, obsessions can also be intrusive nonsense words, music, or other non-threatening thoughts, including "urges" to have something done a certain way, such as touch, tap, rub, or ordering and arranging.
*Please note "obsessions" in the context of OCD should not be confused with being "obsessed" with something one enjoys thinking about such as a celebrity.
Compulsions (also referred to as rituals) are behaviors that serve the function of reducing anxiety/distress from the obsessions, even if they don't seem rationally related to the obsession.
Some examples of compulsions include:
Obsessions cause distress (often anxiety); distress is a feeling that people dislike intensely, and because of that people try to get rid of the distress by doing something that promises to provide relief, which is a compulsion (or ritual). Unfortunately the compulsion/ritual only ever gives temporary relief; the obsession always comes back and the cycle repeats.
Obsessions --> Distress/Anxiety --> Compulsions --> Relief (temporary)
NOTE: Just because somebody doesn't wash or do something repeatedly, does not mean they do not have OCD!