Acne occurs due to excess activation of sebaceous gland in the skin. These are nothing but glands with ducts which produce sebum or skin oil. The purpose of skin oil is to keep the skin smooth and lubricated. For individuals who have acne, these sebaceous gland get overactive and produce excess sebum, and the exit of these sebaceous gland can get blocked due to proliferation. The sebum which gets trapped in the duct can become infected and then inflamed. Sebaceous gland activity is intrinsically controlled by several circulating factors, one of them is androgen. Acne does not occur in individuals who have androgen insensitivity showing the vital importance of androgens in the occurrence and progression of acne.