The skin is exposed to UV rays and accelerates aging. Collagen loss leads to the loss of support around the pores and enlarged pores will be resulted. And its size is related to genetics, hormones and other factors. If the acne is severe or the skin is damaged, destroying the collagen in the dermis of the skin and causing the pores to sink, it will result in depressed pores. Many people love to squeeze "blackheads" and acne, which will destroy the collagen around the pores, make the pores lose support, easy to age and deform, making the coarse phenomenon more obvious.