Acne is a common skin disorder affecting many teenagers. Each hair follicle contains a tiny hair and a sebaceous gland. The sebaceous gland is made up of multiple lobes and it produces sebum. Sebum is an oily substance.
Sebum travels up to the hair follicle and then comes out to the skin.
These sebaceous follicles are blocked and inflamed in acne. Acne develops on those areas of the skin where sebaceous glands are many in number. Mainly you get acne on the face, but it also appears on neck, scalp, chest, back, upper arms and shoulders. Severity of acne increases with the increase of sebum secretion. Androgen hormone, which usually secretes more during teenage, stimulates sebaceous glands and increases sebum secretion, which consequently causes acne.