Why Do I Bite My Nails and How Do I Stop?

Medically Reviewed by Stephanie S. Gardner, MD on January 18, 2022
3 min read

About half of all kids and teens bite their nails. Many don’t grow out of it, either. If you’re an adult who bites your nails, you may have done it when you were younger and just never stopped.

It could be your parents’ fault: Scientists aren’t sure if nail biting is genetic, but kids whose parents bite their nails are more likely to bite their nails, too. Studies show this happens even if the parents stop doing it before their child is born.

Sometimes, nail biting can be a sign of emotional or mental stress. It tends to show up in people who are nervous, anxious or feeling down. It’s a way to cope with these feelings.

You may also find yourself doing it when you’re bored, hungry or feeling insecure. Most nail biting is automatic -- you do it without thinking.

Nail biting won’t typically cause permanent damage. But it definitely has its downsides:

  • It canmake your nails grow in weird. If you damage the tissue around your nails, they may stop growing the way they should. This gives you abnormal-looking nails.
  • It can spoil your smile. You can chip, crack, or break your teeth when you bite your nails. Over time, nail biting can even cause jaw problems.
  • It can make you sick. Hands are a hotbed for germs, and nails are their perfect hideout. When you’re putting your fingers in your mouth multiple times a day, it increases your chances of getting sick. Plus, the skin damage you can cause when you bite your nails creates an easy way for germs to get in.

You may not see a change overnight, but with a little time and effort, you can bust your nail-biting habit.

Try these tips:

  • Cut them short. If there’s not enough nail to grab with your teeth, it won’t feel as satisfying when you give biting a try.
  • Coat them with a bad taste. There are special nail polishes with a bitter flavor you can paint on your nails. The terrible taste will make you think twice before chewing.
  • Splurge on manicures. Spending money and time at a nail salon will give you both good-looking nails and a reason to keep them that way.
  • Wear gloves. It may sound silly, but if you can’t get to your nails, you can’t bite them. If gloves won’t work for your daily schedule, you can look for stickers made to cover nails -- they can have the same effect.
  • Find your triggers. Notice how you feel or what you’re doing when you bite your nails. Once you know what kicks you into nail-biting drive, you can try to find other ways to cope.
  • Keep your hands or mouth busy. Find something to fiddle with -- a stress ball, a worry stone, or even a pen to click. Chew gum so your mouth has a job. Give your nail-biting energy another place to go.

If you’re having trouble with the cold-turkey approach, take it a little at a time. Set small goals for yourself. Try to stop biting the nails on your right hand for a week. Or start even smaller: Choose one nail not to bite, like your thumb. Once you’ve kept it up for a while, put another nail in the “no-biting” zone. Keep going until all your fingers are off-limits.

If you still struggle after trying multiple methods, talk to your doctor about whether therapy’s a good option to help you get to the bottom of the problem and take nail biting out of the picture.

Show Sources

Williams, T.I. Behavior Research and Therapy, May 2007.
KidsHealth.org: "Your Child's Habits."
Mayo Clinic: "Nail biting: Does it cause long-term damage?"
American Academy of Dermatology: "Nail Fungus & Nail Health."
Fiser, J.E. and O'Donohue, W.T. Practitioner's Guide to Evidence-Based Psychotherapy, Springer, 2006.
Ghanizadeh, A. Child and Adolescent Psychiatry and Mental Health, June 2008.
Scher, R.K. and Daniel, C.R. Nails: Diagnosis, Therapy, Surgery, 3rd ed., Saunders Elsevier, 2005.
Tanaka, O.M. American Journal of Orthodontics & Dentofacial Orthopedics, August 2008.

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