Nail biting – not just a habit

Nail biting (also known as Onychophagia) is a common problem (20-30% of the general population) that can persist into adulthood. Usually it is labelled a ‘bad habit’, but it is not always as simple as that, which is why so many people struggle to stop. A psychodermatological approach to breaking the cycle of nail biting can be a way forward.

Why do people bite their nails?

Exactly why people bite their nails is not fully understood. It is however likely to be an interplay of several factors:


Several studies indicate that there is a genetic component to nail biting (also known as onychophagia). One study has shown that 36.8% of nail biters had at least one family member with this habit. Studies of twins have shown that identical twins are more likely to both be nail-biters than non-identical twins.


There has been some suggestion that anxiety is associated with nail biting, but the evidence is not consistent (i.e. some studies show no difference in anxiety disorders between nail-biters versus non nail-biters; but another study has shown that up to 24.2% of nail biters will develop anxiety at some point in their lifetime). Similarly, there has been a noted trend for nail biting among people with obsessive-compulsive disorder (OCD), but this is not proven. Other associated conditions include Tourette syndrome. Childhood psychiatric problems are associated with nail biting (e.g. ADHD, separation anxiety), and nail-biting behaviour has been observed more frequently in children with parents with psychiatric disorders than those without.

Risk factors

Other risk factors that have shown some relation to the development (but not definite cause) of nail biting include low and high birth weight, breast-feeding habits, family conflict, other habitual uses of the mouth (e.g.tooth clenching/grinding), early onset and long duration of bottle-feeding, extensive use of pacifiers/dummies.


Nail-biting behavior is made worse with anxiety, boredom or when concentrating (e.g. working on a difficult task).

How do I identify a trigger?

It is important to be able to able to identify triggers for nail biting, these may include stress, anxiety, or even boredom. To help identify these triggers I suggest keeping a daily journal to write down any thoughts/feelings/situations that promote nail biting (you can write these down in a notebook or even on your mobile phone/laptop/tablet etc.). You may be able to pick up a pattern if you do this, for example ‘I only bite my nails when I am watching TV or bored’. It will then be easier to deal with or stop nail biting. This can be difficult to do on your own, especially if nail-biting is happening largely subconsciously, it may be helpful to enlist someone you trust to make you aware of biting behaviour.

How can I overcome nail biting?

Techniques to overcome nail biting include:


Reprimanding the nail-biting behaviour (‘Stop biting your nails!’) with an aim to stop it is probably more appropriate for children rather than adults! However, in studies, it has not shown to be particularly helpful. 

Habit reversal

Increasing awareness of nail-biting behaviour, predisposing activities, or warning signs, and instead practicing a distracting behaviour (e.g. clasping hands) may help stop nail biting. Habit reversal works on the principle of recognising the behaviour/habit, in this case nail-biting, and then developing a competing behaviour that is performed instead. It is a form of cognitive behavioural therapy and has shown to stop/reverse nail-biting behaviour. 

Object manipulation

Manipulation of an object, for example, a stress ball, can also distract from nail biting behaviour and deliver the same satisfaction. This type of treatment has shown to be helpful for nail biting (but not as good as habit reversal).

Aversion therapy

The practice of applying a bitter tasting lacquer to the nail to deter from nail biting is popular, and a form of aversion therapy. The nail lacquer contains denatonium benzoate and sucrose octaacetate and is available over the counter. This method has shown to improve nail biting.

Non-removable reminder

A wristband or other form of easily visible non-removable reminder can be worn to remind people not to nail bite.

Application of artificial nails or gel manicures 

I hear from my patients that this is a popular technique that they have used with positive results. The obstacle to nail biting is not wanting to ruin their nice new nails/nail paint!

Oral medication

This is only suitable for moderate to severe cases, or in those patients who are developing complications or poor quality of life. Medication can be used in addition to any of the options above. It requires specialist referral to a psychodermatologist or psychiatrist.

Importantly, if nail biting is a sign of another underlying problem, it is unlikely to respond to standard treatment until that problem is addressed (e.g. psychiatric or psychological problem, behavioural disorders).

Websites (set up by the British Association of Dermatologists) (The TLC foundation for body-focused repetitive behaviours)

If anything you read makes you think you may need to see me for advice please book an appointment:

Please follow me on IG! You can also access my videos and interviews on my profile: @the_psychodermatologist


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  • Babar coughlan
    Posted May 3, 2021 2:49 pm 0Likes

    Hello Dr AHMED,

    I hope you are well.

    Whilst, I ” suffer” ( like my youngest son ) with severe ” nail biting”.my oldest son ( who is a Firefighter suffers with severe acne.

    What you’ve mentioned above ( I’ve waited 50 years to have some sort of diagnosis!) And I’ve just seen you on the tv program- re severe acne – powerful message – thanks Babar

  • kathlleen
    Posted September 12, 2023 5:28 am 0Likes

    NAIL BITING – I would have never thought it was a genetic thing. When I married my husband he was and is a severe nail biter. He does it when he’s intensly thinking about something or nervous or very anxious. we had two children, one of which bites his nail. I was raised that you didnt put your fingers in your mouth and especially do not bite your NAILs. I was tought it was a dirty habit. So. . . I did everything I could think of to stop my sons nail biting. Nothing I did stopped husband bits his so severely that he
    hardly has any nails at all, just knub at the end of his fingers. My daughter has never had a problem with biting her nails. My husband’s mother bit her nails. Three of her children, including my husband, bite their nail. And come to find out, my HUSBAND’s grandmother bit her nails. So that’s four generations of nail biting. I would have never thought nail biting would be carried through your genes, but it has to be I have witnessed it.

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