“The 16-year-old boy with a face full of red pimples is considered to be acne, the common causes include the body sex hormone level imbalance, follicle sebaceous gland duct keratinization, Propionibacterium acnes reproduction, immune inflammatory response, etc. In addition, the endocrine factors, bad mood, poor diet, and other factors, will also promote the production of acne. 1. Sex hormone level imbalance: 16-year-old boys are adolescent males, at this time the body secretes a lot of sex hormones, androgen levels rise, and follicular sebaceous glands are regulated by sex hormones, an imbalance of estrogen and androgen levels in the body during puberty will lead to sebaceous glands, sebum secretion increases, clogging the mouth of the hair follicles, easy to cause acne. 2. Keratinization of follicular sebaceous gland ducts: After facial skin is infected with Propionibacterium acnes, the bacteria will hydrolyze the triglycerides in sebum to free fatty acids, which will stimulate the proliferation of follicular duct keratinocytes and over-keratinization of follicular duct keratinocytes, which will block the mouth of the hair follicle and form acne. 3. Propionibacterium acnes reproduction: A large amount of sebum accumulates in the follicular opening, providing a suitable environment for the growth of Propionibacterium acnes, which produces low molecular polypeptides, chemotaxis of neutrophils to produce hydrolytic enzymes, and the formation of pro-inflammatory factors, resulting in the formation of localized acne, and the manifestation of redness, swelling and heat pain. 4. Immuno-inflammatory reaction: the follicle mouth has immuno-inflammatory reaction, the inflammatory reaction will damage the follicle wall, and all kinds of follicle contents will overflow into the dermis, causing inflammation around the sebaceous glands of the follicle, and then produce acne. In addition, acne can be triggered by mental tension, too much stress, and eating oily and sweet foods. Patients are advised to go to regular hospitals for timely treatment after diagnosis.