The toenail is half empty, usually referring to the partial separation of the nail plate and nail bed, clinically common in gray nails, but also seen in a variety of diseases caused by nail dystrophy, etc. 1, gray nail: also called nail fungus, belongs to the fungal infection disease, the initial manifestation of the lateral edge of the nail appear lusterless gray spots, and gradually turn yellowish brown to black. The nail plate will then appear cloudy, thickened, separated, shrunken, peeling, and uneven surface. If patients feel that their toenails have turned gray, they should promptly visit a hospital dermatologist for a fungal examination to clarify the diagnosis. At present, the clinic usually uses terbinafine, itraconazole for oral antifungal treatment, can also choose terbinafine ointment, sertaconazole ointment and other topical topical treatment, if necessary, can also carry out removal of diseased nails or diseased nail extraction; 2, nail dystrophy: refers to a variety of causes of nail morphology and structural abnormalities, can appear nail separation, longitudinal fissures, transverse grooves, atrophy, thinning, rough, cloudy and other performance. Glucocorticoids can be injected subcutaneously into the skin of the nail root for anti-inflammatory as well as immunosuppressive treatment, and recombinant human epidermal growth factor gel can be used to shorten the epidermal repair time and promote the regeneration of normal nail plate and nail bed.