Nail biting: not just a habit

A hand with colourful nailsMillions of adults and children struggle to break through the nail-biting habit. These notes take a closer look at the available literature and treatment recommendations. In addition, information is provided to parents to support their children in overcoming this unhelpful habit.

When it comes to understanding nail-biting, the literature is rather confusing as nail-biting receives a variety of labels from a ‘parafunctional habit’ (which is a habitual exercise of a part of the body that is not a common use - so not eating, drinking, speaking), to self-mutilation (a form of self-harm) and addictive behaviour, category that brings it closer to Obsessive Compulsive Disorder (OCD).

Also known as onychophagia, nail biting is classified under unspecified compulsive and related disorders in the Diagnostic Statistical Manual of Mental Disorders (DSM-5). As nail-biting is experienced as an urge, the treatment does borrow some techniques from OCD treatment such as resisting the urge to bite. What most people do not know is that the more we resist the urge the less of an urge we experience.

But as with hair pulling and skin picking, nail biting is not a disorder unless it is impairing, distressing and severe (interfering with life).

The prevalence of nail biting is probably underestimated. In literature is reported that up to 33% of children aged seven to 10 years and 45% of adolescents are nail biters.

The vast majority of nail biters do not bite their nails severely, however, they complain about experiencing pain, about the non-aesthetic aspect of their nails and about the risks of contracting colds and mouth infections. At the same time, people experience nail-biting as ‘feeling good when you get the nail right’.

Nail biters looking to quit find themselves struggling and many fail in their attempts. The risk of relapse for the recovered nail biters is high. This needs to be accounted for when people embark on the journey of overcoming nail biting so that it can be accommodated into the journey itself.

Many people find that nail-biting occurs during sedentary activities, such as watching TV, reading, driving, or sitting in a meeting. There are times when the nail biter would be engaged in this behaviour with awareness, fully focused, other times people are not even aware they are doing it. Certainly, there is a great deal of mental activity going on and people report worrying, problem-solving, concentrating, processing information that is important or threatening.

The common factor for nail biting is the experience of tension, whether this is experienced as anxiety, discomfort, excitement, concentration or boredom. Normally there is a physical sensation that draws the nail biter towards the nail - skin imperfection, itching, tingling, pain and its associated automatic reactions such as searching for an irregularity in order to remove it and biting.

Many nail biters can trace nail-biting back to their childhood experiences, either copying one of the parents, a sibling, or learning it randomly. It may have been picked up on through association, particularly when a state of tension is experienced and when the person is sensitive to interoceptive stimulation (sensations that originate inside the body). There seems to be some genetic make-up, however, as with any expression of our genes, it is the environment that places its expression on a continuum (whether expressed or not and at what degree/level).

Nail biting is characterised by

  • A feeling of tension (whether this is experienced as anxiety, discomfort, excitement, concentration or boredom) before biting. 
  • The sensation that draws the fingers to the site of biting. These sensations can include skin imperfection, itching, tingling or pain.
  • These sensations associated with tension are experienced as an urge to bite. 
  • Searching for an irregularity in order to remove it and biting.
  • Pleasure, gratification and relief while engaging in the biting behaviour.

With regards to treatment recommendations, the following steps are likely to increase the success rate:

1) As with any Cognitive Behavioural Therapy (CBT) treatment option, the invitation is to get to an understanding of the problem. What does a typical week of nail-biting look like? What is the baseline? Keeping a diary to establish when the nail-biting occurs provides huge amounts of information. Often this stage of the treatment is overlooked. But we encourage people to get into a detective mode, suspend assumptions and start monitoring.

2) It is important to bring awareness on the behaviours and start discriminating between sensations. Is it tension that I am experiencing right now? Is it that I am worrying about something? Is it that I feel pressurised into something? Am I bored? What I am thinking right now?

3) The next stage of treatment requires meeting the body’s needs for stimulation differently than nail-biting. The whole idea is to provide relief whilst discouraging nail biting. At this point people need to explore the use of sensory substitutes:

  • Boredom - find an activity to do.
  • Irregular nail - use a nail file to make the surface of the nail smooth.
  • Tension - relaxation, deep breathing, distraction, grounding.
  • Pressure/discomfort due to blood flow – apply pressure to the whole hand.
  • Fidgety and restless - use an object to fidget with.
  • Dry hands - use cream.
  • Pain - ease pain with warm water, disinfectant/antiseptic.
  • Worries - use worry filter strategies: possibility vs probability, worst, ideal and likely scenario, worry postponement or problem-solving.
  • Feeling concerned - express concerns.
  • Concentration - use hands and mouth in a way that is incompatible with nail-biting, such as chewing gum.
  • Excitement - jump with joy.
  • Tired - have a rest.
  • Angry - express your anger in an assertive manner.

Close-up of a woman with bitten nails, wearing multiple rings
General strategies 
to avoid nail-biting 

The idea of keeping one’s mouth and nails busy is not bad after all. Some people like to drum their fingers, put their hands in their pocket, touch or twist a rubber band, focus on writing, drawing (if engaged with an intellectual activity at the time of the urge).

Keeping the mouth busy goes along the same principles of reducing the amount of time spent nail biting. Chewing gum and sipping water are going to interfere with nail-biting. Putting an obstacle in the way of nail biting is a key recipe for success. There are some products easily purchased from the local pharmacy that will aid the process. And make it easily accessible by carrying it with you all the time.

Each intervention is designed to address the unique sensations that are achieved through nail-biting and therefore are to be taken seriously. It also helps people to handle feelings in a more productive way. As they experience a variety before and after nail-biting, is helpful to identify these feelings and respond to them:

  • Assertiveness.
  • Attending to one’s imperfections with nurturing, looking after rather than harming.
  • Planning ahead with ‘looking after’ one’s nails rather than overusing an emotion.
  • Dealing with unhelpful beliefs associated with nail-biting: I do not care what happens to me. Nothing works. 
  • Accepting the urge without response. Just notice the urge and engage with the above recommended habit reversal/competing responses.

When children are nail-biting, we encourage the parents to get involved. Often the parents’ response involves telling children off for biting their nails, which actually generates tension and more of an urge to bite. By this time the children would have started the process of attending to the nail, making it even more irregular and therefore enhancing the urge.

Motivation can be considered an obstacle for children. Parents are invited to use a reward system to help initiate behavioural change. An effective reward system can be challenging and often misunderstood. Reward charts work better if:

  • The children are involved in monitoring.
  • There is an agreement in place how parents should respond when a child engages in nail-biting.
  • Reminders of recognising the urge and associated sensations.
  • Talking the children through their sensations.

Ultimately, understanding one’s psychological functioning of harming or neglecting a less perfect aspect of themselves and encouraging nurturing and ‘looking after’, offering rewards for successfully abstaining from nail biting and using competing responses.

The moral/key message of these notes is that nail-biting requires experiential re-learning, a nurturing approach to nails (looking after the nails ongoing) and at the time when an urge is experienced, it requires engaging with competing responses, acknowledging the feeling or the emotion experienced and attending to it differently. 

Close-up of a man's hand resting on a notebook, with the words 'let's get started' written on the page.

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