Acne is a kind of acne, the lesions at the beginning are mostly conical pimples consistent with hair follicles, such as whiteheads (closed acne) and blackheads (open acne), the former is a yellow sebaceous angular plug, while the latter is caused by oxidation of the sebaceous plugs; the causes of acne on the body include endocrine disorders, Propionibacterium acnes infections, follicular sebaceous gland ducts keratinization abnormalities, and so on. 1. Endocrine disorders: excessive secretion of androgens in the body will directly affect the secretion function of sebaceous glands, and a large amount of oil secretion accumulates on the surface of the skin, which is the main cause of acne. 2. Propionibacterium acnes infection: acne is a type of acne and a chronic infectious skin disease, in which Propionibacterium acnes is the main disease-causing bacteria. 3. Abnormal keratinization of follicular sebaceous gland ducts: Abnormal keratinization of follicular sebaceous gland ducts will make the ducts of sebaceous glands smaller, or even narrowed and blocked, so that sebum secretion can not be discharged normally, thus forming pimples. There are many causes of acne, so it is necessary to consult a doctor for a consultation and treatment under the doctor’s guidance.