Age spots are also called seborrheic keratosis, the cause of which has not been fully clarified. Age spots on the face in the forties are considered to be related to heredity, skin aging and ultraviolet radiation. 1. Genetic factors: multiple seborrheic keratoses have certain genetic susceptibility, if patients often have family history of the disease, seborrheic keratoses may appear on the face in their forties. 2. Skin aging: seborrheic keratosis usually occurs in adults over the age of forty, and the incidence will also increase with age, and skin damage is accompanied by skin aging and gradually increase, and is considered to be related to skin aging factors. 3. ultraviolet radiation: may be due to long-term chronic ultraviolet radiation, thus prompting the appearance of the phenomenon of face spots, especially the face, neck, upper limbs of the region, will increase the chances of seborrheic keratosis. Seborrheic keratosis on the face in the forties can go to the hospital for examination, and if it affects the aesthetics, if necessary, through laser, freezing or surgical excision and other ways to treat.