The greenish color of the nail cover may be caused by localized bruising, fungal infection caused by onychomycosis, or occupational factors. If the nail has been smashed or hit very hard, it will cause localized bruising, which will make the nail cover appear greenish, usually no special treatment is needed, and the symptoms will disappear after the bruising is absorbed. Infection of Pseudomonas aeruginosa or green Aspergillus and caused by nail fungus can also be manifested as nail cover becomes green. It is recommended to go to the hospital in time, after the doctor’s detailed examination and mycological examination, to clarify the cause of the disease, symptomatic treatment. In addition, some occupational factors can also lead to green nail cover, long-term contact with soap, detergents and so on will lead to the color change of toenails, generally do not need special treatment. Physical abnormalities are recommended to go to the hospital as soon as possible to avoid aggravation of the condition.