Acne occurs when sebaceous glands inside the hair follicles (pores) of the skin become clogged, because emission happens faster than the oil and skin cells can evacuate the follicle. The plug causes the follicle to swell (causing whiteheads), and the tip of the plug may darken (causing blackheads). If the plug causes the wall of the follicle to break, the sebum, dead skin cells, and microorganisms found commonly on the surface of the skin can penetrate the skin and create small infected areas known as pustules (also called pimples or "zits").

The actual pimple is commonly the result of bacteria entering an open skin pore causing the body to respond with millions of white cells to destroy the invaders. As the white cells fight and die they create an inflamed area that turns red (pimple) which over time turns into an even greater mass of dead cells that can create a pus pocket (white head).

Of course open pores can also be impacted with dried oils, external elements or just facial dirt that form what is usually called a black head. Salt from sweat is another cause of many facial break outs when it dries and clogs pores.

Cysts occur when the infection reaches the deeper layers of the skin. A sebaceous cyst forms when the sebaceous gland continues producing oil. Instead of rupturing the follicle wall, the follicle continues to grow and create a soft, pliable lump (called a cyst) beneath the skin. The cyst is commonly not painful or discolored unless it becomes infected.

Acne Scar Causes

Acne scars appear when spots become inflamed or don't heal properly. While scarring for some people seems to depend on hereditary factors or skin color, precautions can be taken to prevent scars and treatments are available to greatly improve scarred skin's appearance.

In the simple terms, scars are the visible reminders of damage and tissue healing. In the case of acne, the damage is caused by the body's inflammatory reaction to sebum, bacteria and dead cells in the clogged sebaceous follicle. Two types of true scars exist:

(1) Depressed areas like in ice pick scars or pitted scarring, and

(2) Raised thickened tissue like in keloids.

When a lesion happens the body rushes in the 'troops' to repair the damage. However, when their job is complete they may leave behind a mess in the shape of fibrous scar tissue, or eroded tissue. White blood cells and inflammatory molecules may stay at the site of an active acne lesion for days or even weeks. For those who are prone to scarring the outcome may be an acne scar.