Acne may be related to genetic factors, endocrine disorders, abnormal keratinization of follicular sebaceous gland ducts, and improper skin care. 1. Genetic factors: acne will have a family gathering phenomenon, has a certain heredity, can affect the distribution of skin lesions and the duration of the disease. 2. Endocrine disorders: acne is mostly related to androgen levels, when the body androgen content increases, sebaceous glands function vigorously, which will lead to a large amount of oil secretion, resulting in acne. 3. Abnormal keratinization of follicular sebaceous gland ducts: when the follicular sebaceous gland ducts are over-keratinized, it will lead to the follicular sebaceous gland’s orifice to become smaller, narrower, and blocked, which will result in the shedding of epithelial cells and sebum can’t be discharged normally, forming pimples or micro-pimples. 4. Inadequate skin care: Incomplete or excessive cleansing of the face, as well as the use of excessively hot water to wash the face, can lead to clogging of the follicle openings or damage to the skin barrier, which can easily lead to the formation of acne. There are many reasons for acne, so patients are advised to go to the hospital in time for a clear diagnosis.