Why do adolescents develop pimples on their back?

The causes of acne on the back in adolescents are complex and varied, mainly including: 1. Hormonal changes: Fluctuating hormone levels during puberty, especially increased secretion of androgens, lead to excessive oil production by sebaceous glands, clogging pores and forming acne. 2. Lifestyle habits: Poor lifestyle habits such as long-term late nights, irregular作息 (作息 should be translated as "作息" is mistakenly used here, but it means "rest and activity patterns"), high stress, and mental tension can affect the endocrine system and worsen acne formation. 3. Improper cleansing: Inadequate cleansing of the back skin or using cosmetics and skincare products unsuitable for one's skin type may also lead to clogged pores and trigger acne. 4. Microbial infection: Infection with microorganisms such as Propionibacterium acnes is also a significant cause of acne. These microorganisms can hydrolyze triglycerides in sebum into free fatty acids, stimulating excessive proliferation and keratinization of keratinocytes in the hair follicle duct, leading to the formation of acne.