#Health & Fitness

Fingernail Biting: Causes and Cures

by Vicki Santillano

Fingernail Biting: Causes and Cures

It’s a nasty habit that for some people, never bites the bullet.


It’s estimated that as many as 33 percent of children under the age of 11 bite their fingernails and that number increases among teenagers and drops off as people reach adulthood. Nail biting—which includes chewing at the cuticles or the skin surrounding the nail, too—occurs more frequently than any other nervous habit (such as hair pulling or thumb sucking). Knowing of so many fellow sufferers has always made me wonder—why do we seek comfort by literally biting the hands that feed us, and just how risky is this act?


Maybe We Can Blame Our Parents
No one knows for sure what causes onychophagia (the medical name for nail biting) or why it starts at such young ages. Stress and medical issues are listed as potential culprits, as are low self-esteem, emotional disorders, and family history. Some believe that genetics play a role in nail biting, as it tends to run in families. Others argue that nail biting is a learned behavior, which would also explain the familial link. If a small child sees her parents biting their nails in times of stress or inactivity, she might try it out and derive pleasure from the action, thus sparking a habit.


A Symptom of Oral Fixation
Freud believed that nail biting, like everything else in life, is related to sex. He believed it was just another characteristic of people with an oral fixation, or the constant desire to put things in our mouths as a form of stimulation. (This might explain why I graduated from nail biting to chronic gum chewing.) According to Freud, all babies go through this stage. If they aren’t treated properly, they never move past this dependency and develop oral fixations. Overeating, smoking, chewing on pens, and even seemingly unrelated behaviors like alcoholism and sarcasm are also listed as oral fixation indicators.


Acceptable at 13, Not so Much at 30
Regardless of the trigger, most kids engage in some sort of nervous habit and nail biting is the most common. It is a way for them to deal with stressful and anxious situations. Because it is such an oft-occurring habit, nail biting is usually not a cause for alarm (i.e., it doesn’t necessarily mean your child has some kind of disorder). The best way to wean kids off their fingers is to figure out what they’re worried about in the first place and address those concerns. The worst thing to do is to threaten punishment or make youngsters feel like they’re doing something wrong. This will only increase their anxiety. Make them aware of the behavior without being negative.


Nail biting is most common between the ages of 10 and 18, and roughly 10 to 15 percent of adults over the age of 30 still bite their nails. Since the majority of people are able to outgrow the habit, why are some unable to kick nail biting to the curb? Like any other stress-related behavior, some are better at controlling it than others. It could be that most people learn to deal with stress in new, less obvious ways or develop other ways to cope with boredom or nervousness. With age comes an awareness of social norms and proper public behavior, so we adopt less public (and therefore more socially acceptable) coping strategies. Plus, some resort to nail biting more frequently than others, so it makes sense that they could abandon it more easily. I wasn’t that much of a nail biter as a kid, but a friend who still bites his nails used to chew them down to nubs when he was younger.


Think About Everything Our Fingers Touch
Part of my escape from onychophagia came with an increased knowledge of just how many germs reside on my hands and underneath my fingernails. After a day of riding public transportation, I barely want to touch myself, let alone put my hands anywhere near my mouth. The area under fingernails is host to dirt, food particles, germs, and a number of other gross items we probably never even consider. All of that is transferred into our mouths as soon as the nails go under our teeth. Just as it’s possible to get pink eye by rubbing your eye with a bacteria-laden finger, you can get sick by putting germy hands into your mouth.


Those who chew the sides of their nails risk infecting the area by opening the skin and letting in germs. The same goes for nail biters who accidentally tear skin with their teeth. Infections in fingers are quite painful and can spread to other areas if not properly treated. Being greeted with pain every time you try to bite your nail might help break the cycle, but it’s probably not the healthiest way to go about it.


Getting the Nail Biting Monkey off Our Backs
No need to break out the Tabasco (especially if you do have open skin near the nail)—there are multiple methods to keep our nails healthy and teeth mark-free.


  • Keep nails short, neatly trimmed, and file them regularly
  • Get a manicure (you’ll be less likely to mess them up if you paid to have them look so nice)
  • Since nail biting is often a sub-conscious act, put something on your nails—Band-aids, stickers—to remind you that you’re about to bite them
  • When temptation hits, reach for a stress ball or find some other way to keep your hands occupied (knitting, writing, etc.) until the feeling passes
  • There are nail biting creams and polishes on the market that taste bitter and are meant to stop nail biting, but some believe they are less effective overall
  • If nail biting is stress-induced, incorporate other forms of relaxation, such as yoga or deep breathing, into your life
  • Hypnosis is sometimes utilized to make the person aware of the habit and find other ways to relax


For being such a strange, inexplicable way to deal with anxiety or tedium, nail biting maintains its position as the nervous habit of choice for many adolescents (and some adults who just can’t quit). Why we continue to pass this habit down through the generations remains unknown, but at least we know there are solutions, and that we’re not doomed to a life of raggedy nails (or tongues burned by Tabasco sauce).