The sudden appearance of spots on the hands may be caused by senile leukoplakia, seborrheic keratosis or flat warts. 1. senile white spots: if the back of the hand of the elderly suddenly appeared white spots, it may be senile white spots or senile anemic nevus, usually and local capillary dysfunction or local aging of the skin, generally do not need special treatment. 2. Age spots: sudden growth of spots on the hands may also be age spots, also known as seborrheic keratosis, usually in the face or the back of the hands, the color is brown or dark brown, usually do not need special treatment, if you feel more beautiful, you can also be through the freezing or laser treatment. 3. flat warts: flat warts are caused by HPV infection, the main symptom is that the affected area will have light brown flat papules, the surface is relatively smooth.