Gray nails are contagious and may be transmitted to babies. Gray nails belong to the nail fungal infectious disease, mainly caused by dermatophytes, mostly caused by direct infection of ringworm. Because the baby’s nails are soft and easily injured, and the baby may like to bite the nails, which can easily lead to small breaks or cracks on the skin around the nails, which can easily make the fungus sticking to the nail plate invade the nail bed, thus leading to the occurrence of gray nails. Since babies’ nails grow faster, the fungus may not have grown enough on the nail to reproduce before the new nail has grown, so babies usually have a lower chance of getting gray nails compared to adults and the elderly. Parents should pay attention to the daily cleanliness of their babies, wash their hands, feet and socks regularly, and do not give their babies shoes that are not breathable. If parents suffer from gray nails, it is recommended that they actively seek medical treatment and avoid close contact or sharing household items with their children, such as footbaths, towels and nail clippers.