The cause of acne is a subject that has been researched extensively by the medical community.  The cause of acne is related primarily to the combined effects of hormonal changes (which in turn affect sebum or oil production), acne bacteria, occlusive (blocking) factors like dirt, scale or hair, and inflammation.  Other factors that may aggravate acne do so through similar mechanisms - increasing oil production, blocking the pores, and/or increasing bacteria production.

• Primary cause of acne - The sebaceous glands increase oil (sebum) production in part due to hormonal changes in the body. These hormonal changes can be related to puberty, menstration, or even menopause. Excess oil that that flows into the hair shaft affects the growth of the protein karatin which makes up "scale". Scale is produced in the inner lining of the hair shaft and when combined with excess oil can lead to blocked follices and pores. The amount of oil produced by the sebaceous glands is not always related to hormonal changes, and those with problem acne often have naturally overactive sebaceous glands.

• Primary cause of acne - Occlusive factors are those substances that contribute to pore and follicle blockages. Occlusive factors include the "scale" noted above, dirt, cosmetics, grease, external oils, harisprays, hats, helmets, and even the hair itself.

• Primary cause of acne - Acne bacteria ( Propionibacterium acnes) occurs normally in the skin. When a blockage of the follicle or pore occurs, p-acne bacteria grow and multiply. The excess sebum acts as a nutrition source for the bacteria, which in turn release chemicals within the follicle. These attract white cells from the blood, and that’s what leads to inflammation and infection. This inflammation is seen as pimples or zits (papules and pustules) on the skin.

• Secondary cause of acne - Common actions that can aggravate acne (or cause more) by causing inflammation are: cleansing your skin too much, squeezing, picking, and popping pimples.  Excessive cleansing, particularly with the overzealous use of abrasive facial scrubs can irritate your skin, and increase inflammation. This inflammation makes it easier for follicles to become blocked.