For mild cases of gray nails with only accumulated edges, self-polishing and topical application can be used mainly. There is no self-treatment for gray nails that are moderate or above. Grey nails are a fungal infection of the nail and are difficult to treat for three reasons: 1. The spores and hyphae of the fungus are infectious and the spores are very resistant to the outside world, so it is difficult to kill them completely. 2, the surface of the nail is hard, and it is difficult to penetrate with topical drugs. 3. The nail grows slowly, and it takes 3-4 months to replace a complete toenail, during which time it is prone to self-infection. So the best way to treat gray nail system of oral antifungal drugs, so that the skin tissue to maintain a certain blood concentration, the fungus has a continuous killing effect. If the lesion is only a little on the edges, it can be treated simply by cutting the diseased nail, thinning it, and applying topical compound benzoic acid solution and 2% tincture of iodine, but for moderate or above, the type that cannot be penetrated by topical medication, self-treatment is very ineffective. Moreover, oral antifungal drugs may cause liver function damage (1% incidence in the population), and need to be prescribed by a doctor and used with regular monitoring of liver function, so it is not recommended to buy them on your own. There are various folklore methods of treating gray nails, but the effect is not guaranteed, or you should choose a suitable and scientific treatment according to your condition.