Gray nails, also known as onychomycosis, are generally not recommended to use oral medications to treat onychomycosis during breastfeeding, and topical medications should be used at the discretion of the doctor’s guidance. Nail fungus is a disease caused by fungal infection of the nail plate and nail bed, etc. Gray nail treatment is based on antifungal. Oral medication for onychomycosis during breastfeeding is usually not recommended because the medication can be secreted through breast milk; if oral medication for onychomycosis is needed, breastfeeding should be stopped. Topical medications such as amorolfine application can be used under doctor’s guidance, but it should be noted that topical medications can be absorbed into the bloodstream percutaneously or secreted through breast milk, and the therapeutic effect of topical medications is limited. Therefore, whether to use topical medications should be used under doctor’s advice and guidance, and discretion should be taken after fully understanding the advantages and disadvantages of such medications. Surgical nail extraction and laser treatment are also available during breastfeeding, but they are painful and of uncertain efficacy, so they are rarely used even by non-breastfeeding patients. It is recommended that patients take oral treatment with antifungal drugs such as terbinafine hydrochloride tablets and itraconazole capsules after the end of the breastfeeding period, and they can try to use photodynamic therapy and other treatments for more stubborn gray nails. Nail fungus patients should pay attention to avoid sharing nail clippers and other items with other people, nail deformation symptoms should be regularly trimmed nails, so as to avoid nail growth into the skin to form ingrown nails.