1, also known as seborrheic keratosis is a kind of seborrheic pigment plaque on the skin of the elderly, which belongs to a kind of benign epidermal hyperplastic tumor, usually appearing on the face, forehead, back, neck, chest, etc., and sometimes it may also appear on the upper limbs and other parts of the body. Sometimes it may also appear on the upper limbs and other parts of the body. It is mostly seen in middle-aged and old people over 50 years old, also known as “longevity spot”, with an incidence rate of about 27% in the elderly. 2, senile freckles: the onset and skin aging, sun exposure, etc., often occurring in the middle-aged and elderly on the back of the hands, forearms and face and other exposed parts of the body, with the increase in age and the increase in the size of mung beans to almonds, brown or black spots. It’s a little higher than the skin surface, the surface is smooth, no pain, no itch, no obstacle to health, but should avoid the sun. 3, old age warts: epidermal benign wart-like proliferation, mostly on the back of the hand, forehead and trunk, etc., was a pinhead cap to soybean size or larger, light brown, dark brown or black, slightly higher than the skin, can also be papillary, often with greasy scales on the surface, soft touch, no pain, no itch, no obstacle to health. If the rash expands rapidly within 6 months, the number increases or accompanied by obvious itching, there is also the possibility of malignant lesions, should be timely to the hospital for examination and treatment.