Due to changes in hormone levels at the onset of puberty, sebaceous glands produce large amounts of sebum under the action of androgens. If sebum is discharged normally, it will appear as a lot of oil without acne. If the sebum is not discharged properly, the sebum will not be discharged, and a closed acne will be formed in the skin. Over time, some bacteria in the skin, such as Propionibacterium acnes, are anaerobic, and the closed conditions are conducive to its reproduction. The sebum becomes its nutrient, and in this closed and sebaceous environment, it multiplies, resulting in some inflammatory reactions. The inflammatory red rash is seen clinically, sometimes with white pustules on top. When the inflammation progresses further, it destroys the walls of the follicular sebaceous glands and their ducts, causing the material from the follicular sebaceous glands to disperse into the dermis. These foreign bodies cause a severe inflammatory reaction in the skin, known as cysts and nodules. These rashes are all manifestations of different stages in acne. These rashes can transform into each other, starting as pimples that are left untreated and, after being squeezed by hand, can become cysts and nodules, or even permanent scars. Acne is a chronic inflammation of the sebaceous glands of hair follicles that occurs in adolescent men and women. The four main factors in the development of acne are: 1) androgens; 2) increased secretion of sebaceous glands; 3) clogged pores; and 4) propionibacterium acnes colonization. In addition, there are genetic, cosmetic, dietary stimulation, immunological factors, endocrine disorders, emotional stress, certain drugs, certain chemical factors such as mineral oil, iodine, and other contributing factors.