Fear of Illness or Contamination
Persons who have this type of OCD, as you can probably guess, worry excessively about their health. Often, they make certain to steer clear of any situation that might present the smallest hint of danger. For instance, they might try to avoid germs by staying away from homeless people (perceived by some to carry diseases), or by staying far away from hospitals where contagion might lurk; avoiding sharp objects that might cut (and thereby infect) them; and so on.
A person with an obsessive fear of illness might also frequently check his body for signs of injury or symptoms of disease, especially after any perceived exposure. He might also engage in the kinds of lengthy hand washing and showering behaviors often associated with OCD.
Ironically, persons with excessive fear of illness sometimes do themselves harm in the effort to avoid it. People who have this type of OCD have been known to wash until they bleed; soak their hands in alcohol, or even harsher solutions, for long stretches; or hold alcohol-containing mouthwash in their mouths for as long as ten minutes at a time, going so far as to allow it to burn their gums in their efforts to combat or prevent perceived illness transmission or contamination.
Another problem (though not a dangerous one) frequently faced by people with OCD is wasted time, often a lot of it. Some people are so morbidly afraid of dirt that brushing up against the tile wall or curtain while showering creates a perceived need for extra showering. Those who have washing compulsions tend to spend an awful lot of time in water.
So-called “checkers” may take hours before they feel ready to leave the house, as they check and recheck the stove, iron, door locks, coffee maker, etc. Similar delays will plague those who must tap doorframes or open and close drawers a prescribed number of times. Most kinds of OCD, in fact, demand a lot of time.
Essential
Sometimes, especially in families or other close groups, persons with one kind of OCD will feel superior to, or have a hard time understanding, those with other types. The reasoning typically goes something like this: “Why don't you worry, as I do, about life-and-death matters, instead of whether the window curtains are straight?” or, “At least my organizational behaviors serve a purpose.”
Fear of Causing Harm
Some people worry excessively about causing harm to others. A person who has this kind of OCD might find himself tortured by the idea that perhaps he ran over a pedestrian and is being pursued by the law. (This is actually a more common anxiety than you might realize.) Or he might fear that he will deliberately cause harm to another.
A surprising number of parents harbor terrifying secret fears that they will become overwhelmed by the impulse to purposely harm their children, even though they know, on some level, that they would never do this. While some parents and caretakers do harm children, it rarely, if ever, happens that a person who has this particular kind of OCD gives in to the kinds of dark impulses he fears.
Other Responsibility Concerns
Some people who have this type of OCD fear that they will be accused of crimes they did not commit — shoplifting, for example — and will find themselves unable to prove their innocence. Or they may worry excessively about spreading germs to others, causing serious illness.
A person who suffers from so-called “responsibility obsessions” might feel the need to check that nobody has in fact been harmed by his actions. He might repeatedly return to a stretch of road, or carefully look over his car for new dents or traces of blood in an attempt to make sure that he did not hit a pedestrian while driving in the dark. He might even call the police to find out whether any hit-and-run accidents were reported during the time he was on the road. Like people with many other types of OCD, he might ask for reassurance almost constantly from a partner or friends.
Fact
People who have OCD often have a hard time making decisions, even relatively simple ones, such as what to eat for lunch or what shirt to wear to work, fearing that a wrong choice could end up having disastrous consequences for them or others.
Checking
As you probably know (or have, perhaps, experienced), some people who have OCD check things, rather than their own bodies. This is the very well known kind that involves frequent scrutiny of stove burners, door locks, ovens and appliances, etc. As seen in other kinds of OCD, irrational doubt and worry are to blame. (“Is the stove truly off? Can I be absolutely sure? Because if it isn't, it could cause a fire in my absence.”)
And, as in other cases, the victim (and, often, her family) suffers a great deal of anxiety, and loses a great deal of time as she goes back again and again to make sure she hasn't left the stove on or the door unlocked. In some cases, door locks and stove knobs are actually broken or seriously worn from such repeated use.

