How Bad Is It Really to Bite Your Nails?

Nail biting may increase your risk of infection and could even damage your teeth.
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How Bad Is It Really? sets the record straight on all the habits and behaviors you’ve heard might be unhealthy.

Nail-biting is generally regarded as a pretty undesirable habit — and not just because it can leave your fingers looking ragged. While nibbling around your fingertip or cuticle might not seem like that big of a deal, it can pose some legit health hazards, especially in our current germ-filled climate.


So what kinds of risks are you really assuming as a chronic chomper? Here's a look at exactly how bad nail-biting is, plus what you can do to quit.

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Why We Bite

Most people bite at their nails or pick at their cuticles every once in a while, especially if you notice something sharp or jagged that needs trimming ASAP. But folks who do it constantly are likely biting as a form of relief from boredom or stress, explains licensed clinical psychologist Aaron Weiner, PhD.

And if you're prone to the behavior, you might find that you do it a lot more during times when things feel really wild and out of control. (Like, hey, a pandemic!)

Get tips on how to stay healthy, safe and sane during the novel coronavirus pandemic.

As for why nail-biting seems to help us deal with uncomfortable feelings? Basically, it's a distraction. Both boredom and stress stem from a sense of restlessness, Weiner explains. "An individual feels an internal energy and is using the behavior to soothe themselves and feel better," Weiner says.


4 Reasons to Quit the Habit

Nail-biting is more common in kids than in adults, and most people kick the habit by the time they hit their 30s, according to the University of Michigan Health System. But regardless of your age, if you frequently find yourself biting your nails, here are a few really good reasons to stop.

1. Nail-Biting Is Basically Eating Lots and Lots of Germs

"Nail-biters get colds and gastrointestinal infections more frequently," says Nikhil Bhayani, MD, an infectious disease physician with Texas Health Resources.


While your hands tend to harbor lots of germs overall, the area around your nails is home to even ​more​ nasty bacteria. The under-nail area around a single fingertip is home to hundreds of thousands of germs, per a landmark May 1988 study published in the ​Journal of Clinical Microbiology​.

That includes illness-causing germs like E. coli, according to a February 2007 study in the journal Oral Microbiology and Immunology.



Not only do your fingertips come in contact with more surfaces than other parts of your hands, but the area under your nails is warmer and more moist than the rest of your hand, making it a cozy breeding ground for nasty bugs.

And when you bite your nails, all of those germs get transferred directly into your mouth, where they can easily infect you, Dr. Bhayani explains. As a result, you're more likely to end up getting sick.


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2. It Ups Your Risk for Skin Infections

Ever have a cut or scrape get dirty and become infected? You run the same risk when you bite. Nibbling at a nail or chomping on a cuticle can break your skin and create small open wounds where bacteria on your fingers can easily creep in.

"When there's a disruption in the skin barrier by nail-biting, this can lead bacteria to deeper layers of the skin, causing infection," Dr. Bhayani says.


That can be both painful and straight-up gross. Infections around your fingernails tend to cause redness, tenderness and swelling around the nail and cause your nail to become hard and thick. And if things get really bad, you can end up with pus that builds up around the nail and eventually oozes out (or worse, has to be removed), per Harvard Health Publishing.

3. It Can Hurt Your Teeth or Gums

As if the whole germ thing wasn't bad enough, gnawing on your nails has the potential to mess with your mouth, too.


"It can have a damaging effect on your tooth enamel over time, leading to chipping or fracturing," says Heather Kunen, DDS, an orthodontist and founder of Beam Street in Manhattan. There are even reports of nail-biters experiencing displaced jaws, according to June 2000 findings in the Journal of Periodontology.


It's not just breaks and chips you need to worry about. "Regularly chewing on your nails can lead to nail fragments and bacteria lodging between your teeth and underneath your gums," Dr. Kunen says. And a rogue nail sitting under your gum line isn't just uncomfortable, it can actually irritate your gums and potentially set the stage for an infection.

4. It Might Make Your Breath Smell

There's not much hard evidence to back this one up. But if you're a nail-biter who struggles with bad breath, it's entirely possible that all the chewing is contributing the stench.

"When we consume dangerous pathogens, we risk oral and systemic infection," Dr. Kunen says. "Consuming these microorganisms could directly or indirectly lead to halitosis, or bad breath."

So, How Bad Is It Really to Bite Your Nails?

Gnawing doesn't just make your nails look gnarly. Putting your fingers in your mouth puts you at higher risk for being exposed to germs — and spreading your germs to others. The dental damage you might incur has the potential to be pretty serious, too.

Added all together, nail-biting is pretty bad — and it's in your best interest to kick the habit. Basically: "Do not bite your nails!" Dr. Kunen says.

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How to Actually Stop

Knowing that you need to chuck the chewing habit is a whole lot different than actually stopping. After all, most nail-biters go in for a nibble without even realizing it — so you might not catch yourself until you're actually mid-chomp.

Even so, wanting to quit is a great first step. And with some smart strategies, you can nix your nail-biting for good.

  • Pay attention to your triggers.​ When you notice times or instances where you bite, you can take steps to steer clear, recommends the American Academy of Dermatology. Tend to go for your nails when you're sitting around waiting and getting bored? Bring a book to keep you occupied.
  • Find another way to keep your hands or mouth busy.​ Keep a stress ball nearby that you can squeeze when you need something to do with your fingers, and have gum handy when you feel like chewing, per the Mayo Clinic.
  • Put a bitter lacquer on your nails.​ You'll immediately get a bitter taste when you put your nail in your mouth. "It makes nail-biting very unpleasant and you'll find that you'll stop in a week or two," Weiner says. Try ORLY No Bite or Probelle Anti-Bite.

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Is this an emergency? If you are experiencing serious medical symptoms, please see the National Library of Medicine’s list of signs you need emergency medical attention or call 911.

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