Gray nail is a fungal infectious disease, although the initial stage is only manifested as irregular small white spots on the side edge of the nail, and then turn into a lusterless gray spot, but the course of the disease is longer, and it is more harmful to the human body, the common hazards are as follows: 1, affecting the aesthetics: nail plate thickening, brittleness, layer, bad crumbling, warping, nail plate middle layer cavitation, jagged nail edges, nail plate and nail bed separation, so the nail plate is mutilated and incomplete, which seriously affects the aesthetics and even causes the patient to have low self-esteem and cause social obstacles. Lead to patients with low self-esteem and social barriers; 2, affecting work and life: finger (toe) nails have great physiological significance to the human body, if the gray nail is more serious, contact with objects may be insensitive, affecting the fine movement and function; and gray nails can lead to pain when serious, which can affect the daily activities as well as the work; 3, contagious: gray nails are contagious, family members, friends will be infected due to intimate contact. Infection: gray nails are contagious, family members and friends will be infected due to close contact. Fingernails or toenails scratching other parts of the human body may transmit the fungus to the body, causing fungal infections in other parts of the body, such as ringworm, tinea corporis, jock itch, etc.; 4. Complications: patients with a long course of gray fingernails, the muscles in the nail are exposed or extruded by thickening of the nail, and once subjected to a variety of traumas, they are prone to secondary bacterial infections, which can lead to complications such as onychomycosis and onychodermitis and may even lead to dandenonitis and cellulitis. etc.