Nail biting or Onychophagia is a pretty common habit, affecting an estimated 30 percent of adults, 45 percent of teens, and 30 percent of children.
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.
Nail biting can be caused by stress, anxiety, obsessive compulsive disorder, or just being bored and fidgety and all these can seem harmless, but you should know that it can invite bacteria or fungi infections to enter into the body and blood stream, increasing your chances of contracting a cold or the flu.
How nail biting leads to bacterial and fungal infections
If you’ve ever had a manicure, you would have 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 that can be found under our nails are Staphylococcus, Streptococcus, and Coryneform bacteria, which can enter the body through breaks in our skin or from ingesting them after biting your nails.
If that is not enough reason to stop you, just imagine dermatophytic fungi, also known as ringworm, hanging out in your nail tissue as you open mouth and insert finger.
How nail biting leads to cold and flu
According to the Centers for Disease Control and Prevention (CDC), there are more than 200 cold viruses 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.
How nail biting can harm your teeth
Nail biting can also damage your 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.
You may want to ask your dentist about having a mouth guard which can help you to stop biting your nails—or at least minimize some of the damage it can cause. They may also help to suggest some other techniques to help you quit the habit for good.
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.