The common causes of white toenail cover are: anemia, onychomycosis, chronic wasting disease, other factors such as exposure to chemical substances. 1. Anemia: anemia in the crowd of the extremities of the end of the blood circulation is relatively poor, and the blood hemoglobin content will be reduced, and toenails often have a lot of capillaries, this time the flow of red blood cells in the capillaries will be relatively reduced, which leads to toenail whitening. In addition, anemia will also be manifested as pale, fatigue and other symptoms. 2. Ringworm of the nails: mainly caused by ringworm infection. It can occur in the fingernail or toenail, and the symptoms such as whitening, turbidity, thickening and shedding of the nail plate appear. So it can also cause the manifestation of white toenail cover. 3. Chronic consumptive diseases: such as hypothyroidism, liver and kidney diseases, malignant tumors, etc., can lead to nail malnutrition, and then appear the performance of toenail whitening. It is recommended to actively treat the original disease. 4. Other factors: if the toenail is in contact with some chemical substances, such as nitric acid, nitrite, etc., it will cause some chemical reactions, which will lead to whitening of the toenail. All in all, toenail cover white, it is recommended to consult a doctor in a timely manner, a clear diagnosis and targeted treatment.