Elderly spots medically refer to seborrheic keratosis, and seborrheic keratosis on the hands of 40-year-olds may be related to factors such as heredity, ultraviolet radiation, and exposure to chemicals. 1. Genetic factors: seborrheic keratosis has obvious family genetic predisposition, and it occurs in people over 40 years old, so age and genetics are important factors affecting the onset of the disease. 2. Ultraviolet radiation: prolonged exposure to ultraviolet radiation or sun exposure will affect the physiological function of the skin, which is also an important factor in accelerating the appearance of age spots on the skin. 3. Exposure to chemical substances: due to the influence of working environment, prolonged exposure to some irritating chemical substances will lead to higher incidence of age spots. There are more factors affecting seborrheic keratosis pilaris on the hands of 40 years old, and it is necessary to consult a doctor first and standardize the treatment under the doctor’s guidance.