How Bad Is It to Bite Your Nails?

Onychophagia, or nail biting, is a pretty common habit, affecting an estimated 20 to 30 percent of the population. Although nail biting—which can be caused by stress, anxiety, Obsessive Compulsive Disorder, or just being bored and fidgety—may seem perfectly harmless, it can invite bacteria or fungi infections to enter into the body and bloodstream, increasing your chances of contracting a cold or the flu, according to the Mayo Clinic.

How bad is it to bite your nails?

Biting your nails might seem like a temporary action, but it could have long-term consequences, according to Raman Madan, MD, the Director of Cosmetic Dermatology at Northwell Health and an Assistant Clinical Professor at Zucker School of Medicine at Hofstra/Northwell. The main issue is that there are lots of germs under your nails. “A study showed that nail biters had E. Coli, a bacteria which can cause stomach issues and more, in their saliva at three times the rate of non-nail biters,” says Dr. Madan.

If you’ve ever had a manicure, you’ve no doubt noticed the gunk that the manicurist removes from under your nails. That’s what you can see with the naked eye—so just imagine all the bacteria you can’t see. The most common pathogens lurking under our nails are Staphylococcus, Strep, and Coryneform bacteria, which can enter the body through breaks in our skin or from ingesting them after biting your nails. If that isn’t enough of a deterrent, just imagine dermatophytic fungi, also known as ringworm, hanging out in our nail tissue when you feel the urge to bite.

Nail biting could lead to a cold or the flu

According to the CDC, more than 200 cold viruses are floating around at any given time. Even though the risk factors for acquiring one include a weakened immune system and/or exposure to someone sick, you can significantly reduce your chances of catching a virus by keeping your hands away from your mouth. Viruses that cause the flu also flourish on your skin, so wash your hands frequently with soap and water (or use an alcohol-based hand sanitizer), and discourage nail biting by chewing gum.

Biting your nails harms your teeth

Nail biting can also damage the teeth and gums. The Academy of General Dentistry has found that nail biting can crack, chip, or wear down the front teeth, and also potentially lead to sore gums and gum tissue damage. Check with your dentist if having a mouthguard can help you to stop biting your nails—or at least minimize some of the damage it can cause. Here are five signs you need to see your dentist ASAP.

Biting your nails makes your fingers more prone to infection

Sure, biting your nails could transfer bacteria from your hands to your mouth, but if you bite your nails to the point where there are tears and openings on your fingernails, there could be even more issues. “There is a condition called chronic paronychia which is a type of infection that occurs when there are tears and openings on your fingernails,” says Dr. Madan. “This allows bacteria and fungus to get in which can be very painful and even more painful if a doctor needs to drain them surgically,” Dr. Madan adds.

Besides, biting your nails could cause permanent damage if you bite down too far and hurt the nail plate, says Dr. Madan. This prevents the nail from growing out correctly and could lead to ingrown or scarred nails.

Next, find out what the colour of your nails says about your health.