Crunch, crunch, crunch. Do you bite your nails? Some kids and adults do this, especially when they're feeling nervous. But it's not a healthy habit.

Here's why:

Your fingernails have a couple of big jobs to do. They protect your fingertips and make it easier for you to pick up tiny things, like loose threads. They also come in handy when you have an itch that needs scratching.

But when you bite your nails, your nails aren't there to do those things. And by biting them, you are breaking the skin and maybe bringing germs into these openings in your skin. In fact, some people bite their nails and cuticles down so far, they bleed! When germs invade, they can get an infection.

Speaking of germs, there are germs under your fingernails, so when you bite them, those germs can go into your mouth. Think about all the icky stuff you touch all day long, like your baby sister's drool-dripping pacifier, your stinky gym socks, or slimy earthworms for your science project. You don't want those nasty germs getting in your mouth.

If you want to stop biting your nails, good for you! Because nail biting is a habit, you may not realize you are doing it. Ask your parents, other family members, or friends to tell you if they notice you biting your nails.

If sheer willpower isn't getting you anywhere, you might want to ask your mom or dad to buy you a special colorless nail polish that makes your nails taste awful. This can help you learn to stop biting them. It may also help keep your nails trimmed and looking good — so good you don't want to chomp on them!

Reviewed by: Steven Dowshen, MD
Date reviewed: October 2010