The sudden whitening of nails cannot be ruled out due to extrusion, anemia, nail fungus and other factors. 1. Extrusion: some patients’ nails may be suddenly extruded by external forces, resulting in the phenomenon of white nail surface, which is a common manifestation. This is a common phenomenon. Symptoms can be relieved after the removal of triggering factors such as extrusion. 2. anemia: some patients may have a decrease in red blood cells, so the patient will not have enough red blood cells in the peripheral blood to supply oxygen to the local tissues or organs, so there will be symptoms of white nails. 3. Nail fungus: nails suddenly turn white, also can not be ruled out due to the skin fungus invasion of the nail bed caused by the nail plate, so the nail plate will appear thickening, turbidity, brittle, discoloration, and shedding symptoms, and stubborn and difficult to treat, recurrence rate is high. There are other reasons why nails suddenly turn white, so if necessary, timely cooperation with the doctor for examination to determine the cause and then do the treatment.