Obsessive Compulsive Disorder is a mental disorder where your brain seems to get "stuck" on an idea or thought, and can't let it go. Some people who have OCD describe it as "mental hiccups" because the thoughts keep reoccurring until something, or several things are done repeatedly to relieve the urge or thought. These thoughts include worries, doubts, or superstitious beliefs brought to an excessive, painful level. The doctor's definition of Obsessive Compulsive Disorder is a "mental disorder which causes problems with information processing.".
Symptoms of OCD always include an obsession, and a compulsion. An obsession is a persistent disturbing preoccupation with an often-unreasonable idea or feeling. Obsession symptoms include forbidden thoughts, a need to have things "just so" or perfect, or a need to tell, ask, or confess. A compulsion is an action or several actions done to relieve the obsession. Compulsions include ordering, arranging, hoarding, saving, checking, or praying. There are hundreds of different symptoms because everyone with this disorder is different.
People that are affected by OCD say that the obsessions are images and urges that occur so repeatedly that it feels uncontrollable. The afflicted person usually doesn't make sense of these ideas, and never wants to have them. The obsessions are usually followed by bouts of fear, disgust, and self doubt. And sensations of guilt and wrong doing.
The OCD affected person describes the compulsion, as the after actions of the obsession. By performing these compulsions, the person is trying to erase all of his or her obsessions. Usually the afflicted person has rules, or rituals, which determine a certain way in which the compulsion must be acted out, such as locking the door five times before bed, or washing hands eight times before any meal. With obsessive compulsive disorder, the compulsions are not a form of pleasure such as drinking or gambling to relieve an obsession, the compulsions that an OCD patient is dealing with are only to relieve them from the even more discomforting obsession.