Someone with Obsessive-Compulsive Disorder suffers from recurring irrational, intrusive thoughts which they can't dispel with reasoning or logical thinking. Most of us get intrusive thoughts "will our family member make it home safe tonight?". However, people with OCD get recurrent distressing intrusive thoughts. To deal with these thoughts people engage in repetitive rituals to reduce the anxiety and stress they are felling.
How can obsessions and Compulsions Present?
Worries about germs, bodily fluids or environmental contamination leading to showering, cleaning and other strategies to prevent contacts with contaminants.
Forbidden sexual thoughts or obsessions which are dealt with by praying, doing a task in 'threes' because three is a safe number or cancelling by replacing a certain 'bad' word with another 'good' one.
Fear of stealing leading to repeating body movements or avoiding certain situations altogether.