Nail biting does far more than ruin your fresh manicure—from bacterial infections to lip warts, these gruesome truths will inspire you to nix the habit for good
Nail biting, technically called onychophagia, may seem innocent enough—in fact, up to 50 percent of us will chronically gnaw our nails at some point in our life, according to a study from the University of Calgary. But experts warn that the nervous habit can have consequences far worse than ruining your pricey manicure. From making you sick to making you look insecure, these 10 science-backed facts are scary enough to make you nix the bad habit for good. (Learn what 7 Things Your Nails Can Tell You About Your Health.)
There's a reason cops and coroners always clean out under a victim's nails on crime shows: Fingernails are perfect catch-alls for dirt and debris. When you chew yours, you're giving all those germs a one-way ticket to your insides, says Michael Shapiro, M.D., medical director and founder of Vanguard Dermatology in New York City. "Your fingernails are almost twice as dirty as your fingers. Bacteria often gets stuck under the nails, and can then be transferred to the mouth, causing infections of the gums and throat."
"Think of every single thing you touch during your day, from doorknobs to toilets," says Kristine Arthur, M.D., an internist at Orange Coast Memorial Medical Center in Fountain Valley, CA. "Germs can live on these surfaces for hours, so when you stick your hands in your mouth, you're exposing yourself to cold and flu viruses, or even serious illnesses like hepatitis." (Learn 6 Ways to Clean Your Place Like a Germ Expert.)
Gel polishes are all the rage, but they're also something that Arthur says is particularly concerning for nail biters. "Regular nail polishes have plenty of toxins themselves, but gel polishes have chemicals that are specifically approved only for topical use, meaning they're not meant to be ingested," she says. "It may take a long time to build up a toxic level in your system, but do you really want to take that chance?"
"Chewing exacerbates dry skin, making peeling worse and leading to more hangnails," Arthur explains, adding that people who chew their nails often use their teeth to peel off hangnails, leading to a tear becoming longer and deeper. (We'll wait while you finish shuddering.)
Worse, hangnails are open sores which can easily get infected, Shapiro says. The best way to avoid the painful sores is to prevent the hangnail from forming in the first place by moisturizing regularly—and not chewing on your fingers.
Whether or not the stereotype is true, nail biters often put out a self-conscious vibe. "Most people bite their nails to seek comfort or relief from a negative emotional state, such as distress, shame, anxiety, or boredom," says Mary Lamia, Ph.D., clinical psychologist and professor at the Wright Institute in Berkeley, CA. "In a sense, nail biting attacks the self, which tends to result in publicly exposing one's feelings of shame and of disgust about the self." (Try one of these 15 Easy Ways to Beat Everyday Anxiety instead.)
Facial warts aren't just for wicked witches: "Warts on your fingers can be caused by human papillomavirus, or HPV," Shapiro says. "These warts can easily spread to other fingers, your face, your mouth, and even your lips," adds Arthur.
Chia pets too much maintenance? You can grow your own pet organism on your fingertips. "Nail biters are particularly susceptible to paronychia, a skin infection that occurs around your nails," Shapiro explains. He says that chewing your nails can allow yeast, fungi, and other microrganisms to set up shop under and around your nails, leading to swelling, redness, and even oozing pus.
Biting isn't just bad for your fingers, it's also bad for your teeth. "It can interfere with proper dental occlusion, or the manner in which your upper and lower teeth come together when you close your mouth," Shapiro says. "Plus, your teeth may shift out of their proper position, become misshapen, wear down prematurely, or become weakened over time." (Learn what 11 Things Your Mouth Can Tell You About Your Health.)
Instead of having a Pinterest-pretty mani, nail biting—especially when you bite the nails down to the quick (the nail bed)—can make your fingers look pretty gnarly. And we're not just talking about the stubby, ragged look. You could cause them to grow in unevenly or with bumpy ridges, Arthur says.
Most of us are familiar with ingrown nails on our toes but, according to Shapiro, biting your nails can lead you to get them on your fingers as well. Worst-case scenario, ingrown nails can get so bad they cause infection and can even require surgery. Best case, you still get all the swelling, redness, and pain you know and loathe.