The usual causes of white spots on finger nails are: nail psoriasis, onychomycosis, nail trauma and so on. 1. Nail psoriasis: it can be caused by genetic factors and environmental factors. Clinical manifestations of psoriasis often include nail thimble-like changes, nail separation, loss of nail luster, and white spots, etc. Usually, changes in nails are related to the extent of extensive skin lesions. 2. Onychomycosis: caused by dermatophytes invading the nail or nail plate. Ringworm of the nail has many types, among which superficial white ringworm of the nail will lead to the superficial layer of the nail plate to appear dotted, flaky white turbidity, the phenomenon of white spots on the fingernails. 3. Nail trauma: if the nails are squeezed and the nail matrix is damaged, the phenomenon of white spots on nails will easily appear. 4. Other: some internal medicine system diseases can also make the nail change, such as renal anemia, liver disease, tuberculosis, etc., can also lead to the symptoms of white spots on the nail. To summarize, if white spots appear on nails, it is recommended to go to regular hospitals for examination and treatment to avoid aggravation of the condition.