10 Nervous Habits That Hurt Your Health

bite-nails
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You bite your nails

It's one thing if you nervously bite your nails only during scary movies, but when it becomes a regular habit, it can damage both your nails and the skin around them, says Michael Shapiro, MD, a New York City-based dermatologist. Germs from the mouth get transferred to the skin, and vice versa. "Bacteria under the nails may also be transferred to mouth, causing infections of the gums and throat," Dr. Shapiro says. Painting your nails may discourage you from chewing. No dice? Try tape to break the habit.

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