This is a common sign of nervousness, tension, excitement, or worry in a child. It may indicate fear and anxiety or may be an expression of repressed anger.
Treatment is directed to allaying the fear, anxiety, or nervousness and to trying to provide more stable emotional support for the child. Punishment for this habit is usually useless and often only aggravates the condition. Putting ill-tasting medicine on the nails and shaming or punishing the child usually intensifies nail-biting. A child who bites his nails out of boredom or lack of interests should be directed toward some meaningful activity to keep his hands occupied.