Obsessions are thoughts, images, or ideas that won't go away, are unwanted, and cause extreme distress. For example, you might worry constantly about becoming contaminated with a deadly disease; that you will do something terrible, like scream out an obscenity at a funeral; or that something horrible will happen to a loved one. Other common obsessions include repeated doubts, such as believing you may hit someone with your car; a need for order; aggressive or disturbing ideas such as thoughts of murdering your partner or child; as well as disturbing sexual and religious imagery.
Compulsions are behaviors that you feel you must carry out over and over. For example, if you are obsessed with contamination, you might wash your hands over and over again. Other common compulsions include cleaning, counting, checking, requesting or demanding reassurance, and ensuring order and symmetry.
OCD affects about 2.5% of people over their lifetime. There is no difference in the rate of OCD among men and women. People of all cultures and ethnicity are affected.