The white color of toenails may be caused by white spots, gray nails, psoriasis and other reasons. 1. Nail white spots:Nail white spots are the manifestation of toenail malnutrition, the functional state of the nail matrix as well as the peripheral circulation function is not ideal, resulting in the symptoms of white toenails. 2. Gray nails: gray nails are infected with fungus after the formation of nail fungal disease, fungal infection of the nail plate, resulting in the dissolution of the nail plate, the cuticle degeneration and brittleness, and at the same time appeared to whitening and thickening and other symptoms. 3. Psoriasis: a disease caused by a combination of genetic, immune and environmental factors. When the toenails are involved, white scales in the form of dots or flakes will appear, and the nails will also appear white. If the symptoms of white toenails appear, it is recommended to consult a doctor in time for examination, to clarify the cause, and under the guidance of the doctor, to take the corresponding treatment plan.