Gray nails, also known as onychomycosis, are usually infectious nail lesions on the hands or feet caused by fungal infections. A large number of pathogenic fungi gather in the nail plate and nail bed, and a large number of pathogenic fungi are found in the gray nail shavings that fall off at any time. Couples who have close daily contact with each other can be infected through direct or indirect contact. If the other spouse has poor body resistance or has a broken finger (toe) nail, the likelihood of infection is higher. If one of the spouses has gray nails, they should not share hygiene products with their family members, such as towels, bath towels, foot mats, slippers, nail clippers, as well as foot baths and bathtubs, etc. They should be cleaned separately. At the same time, patients should pay attention to their personal hygiene habits, and should regularly clean and disinfect the products that are used a lot, and gloves and shoes and socks should be frequently dried in the sun to keep them dry. In addition, patients still need to actively seek medical advice and take oral terbinafine and itraconazole for antifungal treatment, and can also choose terbinafine ointment and sertaconazole ointment for topical treatment. If necessary, nail debridement or laser and photodynamic treatments may be required.