Pimples are generally referred to as acne, which may be caused by abnormal androgen levels, clogged follicular openings, and inflammation. 1. Abnormal androgen levels: After puberty, the level of androgens in the body will increase, which will cause the sebaceous glands to enlarge, cortical secretion to increase, and oil and shedding of dead skin cells will lead to clogging of the pores, resulting in acne. 2. Clogged follicular opening: If the surrounding cells are abnormally keratinized, the follicular opening will become smaller and narrower, so that the cortex can not be discharged and accumulate in the follicular opening to form acne. 3. Inflammation: As adolescents continue to develop and mature, the secretion function of sebaceous glands will continue to increase. Fatty acids and other components within the sebum are beneficial to the growth and reproduction of Propionibacterium acnes, which can cause acne, and at the same time, Propionibacterium acnes will also damage the tissues around the follicles, causing the spread of inflammation. There may be other reasons for the formation of acne, it is recommended that patients go to the hospital in a timely manner, under the guidance of the doctor targeted treatment, life should pay attention to skin cleansing and care, to promote recovery.