Initially, nail-biting is typically a relatively non-destructive, cosmetic issue that is merely a cosmetic concern. However, it may develop into a more serious, long-term issue. An onychophagia, or onychophagic disorder, is characterized by chronic, seemingly uncontrollable nail-biting leading to damage to fingertips and adjacent tissues.
Onychophagia and some related behaviors like lip-biting and cheek chewing are classified in the DSM-5 as obsessive-compulsive disorders treated as body-focused repetitive behaviors. Treatment is tailored to address the physical as well as psychological aspects involved with nail-biting.
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It may occur alone or may coexist with other body-focused repetitive behaviors (BFRBs) like hair pulling (trichotillomania) or skin picking (excoriation disorder). Onychophagia disorder commonly results in visible damage to fingernails, cuticles, and other surrounding areas. Symptoms of onychophagia include both physical and psychological ones. People who habitually bite their nails may also experience the following symptoms in addition to a compulsive urge:
- Feeling stressed or anxious before biting
- Relieved or even pleased after biting
- Biting of the skin or nails can result in feelings of shame, embarrassment, anxiety or guilt
- Being disgusted by or seeing one’s nails
- Family or social relationships can be strained or complicated by either intentional social withdrawal or ridicule or shaming by others for the behavior
- Fingernail, nail and cuticle damage
- Tooth injury, dental problem, abscess and infection
You may be unaware that you bite your nails or you may be focused on it. Early childhood and adolescence are usually when it first becomes evident. In many cases, the behavior stops in late adolescence or early adulthood, even though it may continue into adulthood.
Related: Nail Picking Disorder
Is nail-biting a mental health problem?
The act of biting your nails is relatively common, but it is hard to determine if it is “normal” or pathological. Diagnostically, DSM-5 defines body-focused repetitive behavior disorder (which includes onychophagia) as causing clinically significant distress, causing significant interference in at least one important life domain, and resulting from repeated, unsuccessful attempts to stop the behavior. Thus, anyone who feels deeply ashamed, guilty, or troubled by their nail-biting, feels unable to stop and finds that it interferes with one or more aspects of their life should seek treatment.
What are the side effects of nail-biting?
Nail-biting can damage the skin and nails, cause skin infections, cause fungal infections, and lead to mouth pain or tooth decay. If the bitten nails are swallowed, they may also get stomach and intestinal infections. Biting nails and fingers may cause internal infections or digestive problems since bacteria and viruses are often found on nails and fingers.
Can nail-biting cause long-term damage?
The possibility of long-term or serious consequences of a nail-biting habit exists, but they are rare. When fingernails are not biting, they grow normally, and they have been shown to have little impact on growth over the long run. The most serious risk of long-term infection comes from skin, stomach or intestine infections. These infections are usually treatable, however. Occasionally, nail-biting can cause dental problems (such as chips in the teeth) that will require treatment.
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When does nail biting typically begin?
Children usually begin biting their nails when they are 3 or 4 years old. The prevalence of persistent nail biting in children younger than 3 is relatively low. Occasionally, an adult begins to bite their nails suddenly; it may also begin in adolescence.
How common is nail biting?
It is believed that nail-biting is the most common repetitive behavior focused on the body. 20 to 30 percent of the population bites their nails, according to the most commonly cited research. The majority of nail-biting occurs in children and adolescents, with some estimates suggesting that nearly forty percent of children and nearly a half of adolescents bite their nails.
Nail biting causes
Genetic factors may play a role in onychophagia; some individuals seem to have an inherited tendency to develop BFRBs and to have higher-than-average rates of mood and anxiety disorders in close family members. There is a strong link between nail-biting and anxiety because chewing on nails is reported to relieve stress, tension or boredom.
When people bite their nails habitually, they often feel nervous, bored, lonely or hungry. It is also possible for nail-biting to develop from earlier thumb- or finger-sucking habits. There is no evidence that nail-biting is related to any other psychiatric conditions, but it may occur in conjunction with attention-deficit/hyperactivity disorder (ADHD), oppositional defiant disorder, separation anxiety, enuresis and tic disorders.
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What causes excessive nail biting?
It’s not known exactly why some people bite their nails, but others don’t. In addition to known neurological roots, nail-biting appears to run in families to some extent and may be associated with mental health disorders such as OCD and anxiety.
There is also the possibility that nail-biting may be caused by an overall tendency toward perfection in one’s personality, or by a desire to stimulate oneself when bored. An adult who begins biting his or her nails suddenly may be experiencing the side effects of medication.
What are the most common triggers for onychophagia?
Onychophagia is characterized by biting your nails for a variety of reasons. Biting may be a reaction to worry or stress, boredom or under-stimulation, or it may be a reaction to being mentally engrossed in another activity. It is often critical to an effective treatment plan to identify one’s own triggers and establish substitute behaviors.
There are some old-fashioned remedies for preventing nail biting disorder, such as applying bitter-tasting products directly to the nails, but today’s versions are generally less effective for individuals who have persistent, compulsive onychophagia. There may be greater effectiveness with barrier-type interventions, such as gloves, mittens, socks, and bite-plate or retainer devices, that block contact between the mouth and nails, which both serve as physical reminders not to bite as well as impediments to biting. The problem is that they can be difficult to use consistently or for long periods.
Professional treatment is often helpful in cases of onychophagia that are more severe, particularly when it focuses on finding and managing the emotional factors that contribute to nail biting. There is some evidence that cognitive behavioral therapy (CBT) and acceptance and commitment therapy (ACT) can benefit people with BFRBs, especially when combined with habit-reversal training and/or progressive muscle relaxation. Positive reinforcement is necessary along with routine follow-ups and positive reinforcement in order to treat onychophagia successfully.
Is therapy effective for nail-biting?
Yes. The treatment of nail-biting, especially cognitive behavioral therapy (CBT) or cognitive action therapy (ACT), can help identify and manage the repeated thoughts and emotions that trigger it. Habit reversal training (HRT) is a type of therapy that specializes in identifying biting triggers, finding replacement behaviors (such as squeezing a stress ball or balling one’s fists), and developing social support.
Treatment with HRT, especially short-term treatments, has proven highly effective for BFRBs, but long-term treatment requires a more comprehensive approach that also includes cognitive and behavioral components.
Is it possible to treat excessive nail-biting with medication?
Many of the medications prescribed to treat anxiety and depression also help some patients reduce their nail-biting. SSRIs have been observed to reduce nail-biting in some patients. N-acetylcysteine may reduce nail-biting behaviors more effectively than a placebo, according to some studies, though more research is likely needed. The supplement is also being investigated for trichotillomania and excoriation disorder.
Are there any self-help strategies to reduce nail-biting?
Wearing gloves or mittens can make biting less appealing, as can cutting nails short or painting them with bitter-tasting polish. It can also be helpful to use tools to make a person’s nails less attractive to bite.
Furthermore, one should understand their “triggers”-the emotions or situations that cause them most to bite-and develop coping mechanisms that replace biting with healthier alternatives. In the case of someone who bites while bored, playing with a fidget toy could keep them occupied, and if they bite when anxious, squeezing a stress ball could help to calm their nerves.