The yellowing of the toenails is considered to be onychomycosis, and the treatment is divided into topical medication and internal medication. Topical medications are commonly used for superficial and non-involved nail root damage. Usually use a knife or nail file to scrape off the nail as much as possible, and then apply 30% glacial acetic acid solution or 3%-5% iodine tincture twice a day, the course of treatment is 3-6 months until the new toenail grows out for; you can also use 40% urea ointment sealing package, so that the disease of the nail softening peeling off, and then use the topical antifungal preparations. Internal drug treatment, you can choose itraconazole intermittent shock therapy, that is, 400mg / d, divided into 2 times orally, monthly medication for 1 week, for a course of treatment, toenail involvement requires 3-4 courses of treatment; can also be used to terbinafine 250mg / d orally, usually requires 6 courses of treatment, that is, 6 weeks, and the combination of topical medications can improve the efficacy of treatment.