OCD sufferers experience obsessions which take the form of persistent and uncontrollable thoughts, images, impulses, worries, fears or doubts. They are often intrusive, unwanted, disturbing, significantly interfering with the ability to function on a day-to-day basis People with OCD often realise that their obsessional thoughts are irrational, but they believe the only way to relieve the anxiety caused by them is to perform compulsive behaviours, often to prevent perceived harm happening to themselves or, more often than not, to a loved one. Compulsions are repetitive physical behaviours and actions or rituals that are performed over and over again in an attempt to relieve the anxiety caused by the obsessional thoughts.