Causes of white toenails may be related to white nail disease and onychomycosis. The treatment needs to be targeted according to the different causes. 1. White Nail Disease: Generally related to vitamin deficiency, heredity and other factors. It is divided into point-like white nail, linear white nail, partial white nail, and total white nail. Treatment, if it is caused by heredity, and no other symptoms, do not need special treatment; if it is caused by lack of vitamins, you can supplement the appropriate vitamins, and do not bite nails in life. 2. Ringworm of the nail: it is due to the ringworm bacteria invading the nail bed or nail plate leading to toenail lesions. Symptoms are manifested in the early local nail color change, may be white, dirty color, yellow and so on. For treatment, you can use antifungal drugs such as fluconazole, itraconazole, terbinafine, and amorolfine applicator. It is recommended to consult a doctor in time to identify the cause of the whitening of toenails and treat the symptoms. The above medications should be used in accordance with medical advice.