The unevenness of the fingernails of a 3-year-old child is generally not a normal situation, it may be caused by long-term nail biting, or it may be caused by diseases such as onychomycosis. Need to go to the hospital dermatology consultation, clear cause and then treatment. 1. Many children have the habit of biting their nails, and the fingers that children love to bite are usually the thumb and the finger, which are characterized by uneven and broken fingernails. As the child grows up, the habit of biting nails will be reduced, and the symptoms of uneven nails will also subside, usually parents should try to minimize the blame on the child, to avoid the baby overly nervous. 2. Ringworm is caused by fungal infection of the nails, and many children are infected by animals or by their parents. Many children are infected by animals or their parents. Nails lose their luster and have many small pits. In severe cases, the nails become thicker and change shape. Nail fungus can be treated with topical medications such as povidone-iodine applicator and amorolfine applicator. If a 3-year-old child has the above symptoms, it is recommended to consult a doctor and follow the doctor’s instructions for targeted treatment.