The movies "World War Z" ($202 million), "What Lies Beneath" ($155 million) and "Gremlins" ($148 million) are the all-time, top-grossing nail-biters in North America, scaring tens of millions of moviegoers. But nail-biting isn't always so entertaining.

In fact, it's an affliction that may indicate you have a condition associated with obsessive-compulsive disorder. The condition is called body-focused repetitive behavior, or pathological grooming.

Experts say nail-biting is a clue that you're not handling stressful, frustrating, dissatisfying, or boring situations effectively, and that you're inclined to create short-term, self-soothing habits instead of discovering positive ways to make yourself feel better in the long run.

Researchers have found that people do report that nail-biting immediately feels soothing.

In addition, the American Academy of Dermatology warns that repeated nail-biting can harm the nail bed and lead to abnormal-looking nails. It also can pass bacteria and viruses from your mouth to your fingers and back.

So how can you stop?

Keep a journal that identifies nail-biting triggers; you'll begin to see when the urge strikes. That will help you resist.

When you can't beat the urge, substitute squeezing a stress ball for nibbling.

Keep your nails short, and consider using a bitter-tasting nail polish to make it unpleasant to put your fingernail in your mouth.

Then think about adopting long-term stress busters, like mindful meditation or yoga.

If you still can't beat it, cognitive behavioral therapy or holistic psychotherapy may be smart steps.