The causes of acne on the neck, i.e. acne vulgaris, include overproduction of sebaceous glands in the neck and propagation of Propionibacterium acnes, as well as dietary and other related factors. The sebaceous glands in the neck secrete increased sebum due to increased androgen levels after puberty or imbalanced estrogen and androgen levels. Sebum provides conditions for Propionibacterium acnes to multiply in the hair follicles. Propionibacterium acnes can promote hyperkeratosis of keratin-forming cells at the follicular ducts, which can block sebum excretion. At the same time, it can activate the immune-inflammatory response, leading to the development of acne. In addition, there are genetic, immune, endocrine, emotional and dietary factors associated with acne. It is recommended that acne on the neck be treated promptly by a medical professional.