White spots on the middle finger nails may be caused by nail malnutrition and gray nails. 1. Nail malnutrition: If there is a lack of iron or zinc trace elements in the body, it may lead to malnutrition of the nails and white spots may appear on the nails. 2. Gray nails: If the nails are infected by fungus, the nails may become discolored. There are many reasons for white spots on the nails of the middle finger, and it is recommended that this group of people go to a regular hospital in time to clarify the cause of the disease and carry out standardized treatment under the guidance of the doctor, so as not to delay the disease and bring adverse effects on the body. We also need to pay attention to the comprehensive and balanced nutrition, not picky, not partial food, in order to prevent the body lack of micronutrients.