How To Stop Biting Your Nails

A psychologist and a dermatologist explain what causes nail biting, the health risks associated with it, and tips to quit.

Whether it’s a chronic issue or just an occasional nervous behavior, nail biting can be a challenging habit to break. According to studies, 20% to 30% of people in the United States, spanning all age groups, habitually bite their nails, a disorder known as onychophagia.

According to Dr. Rachel E. Ginsberg, a psychologist at NewYork-Presbyterian/Columbia University Irving Medical Center, nail biting could be a sign of something more significant, such as underlying anxiety. Dr. Shari Lipner, the director of the nail division and a board-certified dermatologist who specializes in nail disorders at NewYork-Presbyterian/Weill Cornell Medical Center, warns that the habit can lead to infections and even permanent nail damage.

Health Matters spoke to the two experts to better understand the condition, why people bite their nails, and effective strategies for quitting.

Dr. Rachel E. Ginsberg

What causes people to bite their nails?
Dr. Ginsberg: Nail biting can be prompted by many internal and external factors. If you’re feeling stressed or frustrated, it can help to instantly self-soothe. For some people who are feeling bored, restless, or overstimulated, it can help them focus. Nail biting can become an automatic coping mechanism to regulate emotions and bring relief at the expense of fueling a distressing habit. When it becomes chronic, it can be difficult to break the habit, particularly because many people go into a trance-like state, and often automatically default to biting their nails.

It also appears that if you have family members who are chronic nail biters, you might be more prone to nail biting yourself. One survey-based study at a pediatric outpatient clinic found that 63% of pediatric patients (ages 3 to 21) who engaged in nail biting identified at least one other family member with this condition.

When does nail biting become an issue to be concerned about?
Dr. Ginsberg: The reality is that nail biting is a comforting behavior in the moment. If people become reliant on it to regulate their feelings or their focus, that’s when we’d want to find alternative ways to cope.

Nail biting, repetitive or chronic, is classified as a body-focused repetitive behavior (BFRB) and falls under the category of “other specified obsessive-compulsive and related disorders” in the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders (DSM-5-TR). Body-focused repetitive hair pulling, skin or nail picking, lip biting, and cheek chewing/biting fall under this category.

Portrait of Dr. Shari Lipner

Dr. Shari Lipner

What does nail biting do to your nails and the surrounding skin?
Dr. Lipner: Short term, nail biting can cause breaks  and cuts in the skin around the nail, which may be painful. Open skin is an entry point for microorganisms; if bacteria gets in, you could get a staph infection, which may be mild, or it may form an abscess that needs oral antibiotics and drainage. Nail biting may also predispose to viruses.

It’s common for people who bite their nails to develop warts. Warts are difficult to treat in general, and warts around and under the nails are even harder to treat, especially when they get under the nail. It’s a long, painful process. To make matters worse, the warts may spread to the lip area, which is also not a pleasant treatment because it’s very sensitive skin.

If people bite long term, the nail itself becomes shorter over time. If you damage the nail bed (the area under the hard part of the nail) you start to see a shortening of the nail such that it only grows to a certain point. Unfortunately, that can be irreversible if the person has bitten their nails for many years.

What are some other habits and behaviors that are related to nail biting?
Dr. Ginsberg: About 25% of people who bite their nails also have an anxiety disorder. If you engage in nail biting as a primary or prominent coping mechanism, and you don’t learn other tools to help manage your emotions, then you might struggle with longer-term symptoms related to anxiety, mood, or executive functioning. It’s not that one causes the other, but it could be a sign that your mind and body are trying to internally soothe underlying feelings, or ‘split off’ intense feelings. Some studies also show that nail biting often runs higher in people with ADHD and tic disorders.

Dr. Lipner: The most common habits that I have seen that go hand in hand with nail biting are nail picking and nail rubbing. The skin near the cuticle is your nail growth center, or the nail matrix. If you rub or press that area too often, it will cause horizontal indentations in the nail that resemble a washboard. The nail will go grow thinner in that area each time you put pressure on the nail growth center. The good news is, when people stop the habit, the ridges will eventually grow out. The fingernail usually takes six months to replace itself.

Why is nail-biting so difficult to stop?
Dr. Ginsberg: Nail biting acts as a natural pacifier. It’s very hard to resist the urge to do something that brings immediate satisfaction or relief.

Nail biting occurs across a spectrum. Some might only bite when they are anxious at work or while watching a “nail-biting” thrilling movie or sports game; they might catch themselves doing it and stop. Others might experience an intense urge to constantly bite their nails throughout the day. Many think that if people bite their nails until they start to bleed or hurt,  they would intuitively stop. But that’s not always the case in those who struggle with chronic nail biting. Even with pain, burning, or inflammation, they might feel a strong urge to continue and persist.

Tips To Treat Nail Biting

Start with Awareness Training
This strategy involves logging information when you feel the urge to engage in nail biting, such as cataloging the details leading up to each episode and identifying the thoughts and emotions that precede nail biting. You can then start to see patterns that allow you to become more mindful and aware of the circumstances that lead to related urges and behaviors, and gain a sense of self-awareness about the environments (such as while driving or doing schoolwork), times of day, and related sensory and cognitive factors that contribute to nail biting (such as times of high tension or hyperfocus).

Find a Competing Response
Identify ways that block or make it impossible for you to bite your nails. This could be as simple as making a fist or sitting on your hands until the urge passes, putting a Band-Aid on the finger that you’re most likely to bite, or applying lotion to your hands. “Using lotion or a skin protectant ointment can change the sensory stimulation: It probably won’t taste good, but it helps soothe the frayed edges of skin, nails, and cuticles that often trigger people to bite or pick,” says Dr. Ginsberg. “Getting regular manicures is also a useful tactic, as the visual reminder and active choice to engage in self-care may discourage you from biting.”

Identify Alternative Ways to Self-Soothe
A recent study found that using a “gentle touch” replacement option helped people stop biting their nails. Any time you feel the urge to bring your fingers to your mouth, you can choose to practice a new, harmless technique instead. “You’re looking for something purposeful, comforting, and intentional,” says Dr. Ginsberg. It might be rubbing your thumb and your index finger together or tracing circles on your hand. “It’s benign and not obvious, and it allows you to feel a sense of agency and embrace the freedom to choose your response,” she says.

Try Taking a Supplement
N-acetyl cysteine, or NAC, is an antioxidant and amino acid that could help treat chronic nail biting. “It’s an over-the-counter pill that affects the levels of glutamate in the brain and helps some people with body-focused repetitive behaviors break their habits,” says Dr. Lipner. One study showed that NAC was well tolerated and helped decrease chronic nail biting in children and adolescents after two months.

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