Gray nail that is nail fungus, nail fungus patients alone external ointment effect is not good, clinical generally do not use the external drug treatment alone, the efficacy can not be guaranteed, some patients may use the drug after 3~6 months to see the effect. Nail fungus is mainly caused by dermatophytes invading the nail plate, and the patient’s nail plate will appear thickening, turbidity, separation and other symptoms. Because the topical ointment can’t penetrate the nail plate very well, clinically, the topical medication is not the main treatment, and there is no authoritative data to show how long the topical ointment alone can be effective. In general, it may take about 3 months for the therapeutic effect to appear. If the disease is more severe, the time to see the effect of topical ointment alone may be extended, and the effect may also be seen in about 6 months. Patients can combine oral antifungal drugs for treatment, such as itraconazole, terbinafine, etc., to play the role of antibacterial and antiseptic, which can make the course of the disease shorter. For patients with onychomycosis, it is recommended to go to a regular hospital, under the guidance of the doctor for treatment, and not to use medication without authorization.