Acne appears when sebaceous glands inside the hair follicles (pores) of the skin become plugged, because emission happens faster than the oil and skin cells can evacuate the follicle. The plug causes the follicle to bulge (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 microbes found commonly on the surface of the skin can penetrate the skin and create small infected areas known as pustules (also known as pimples or "zits").

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

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

Cysts occur when the infection reaches the deeper layers of the skin. A sebaceous cyst appears when the sebaceous gland continues to produce oil. Instead of breaking the follicle wall, the follicle continues to enlarge 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 cure properly. While scarring for some sufferers seems to depend on hereditary factors or skin color, precautions can be taken to prevent scars and treatments are available to significantly reduce 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, microbes and dead cells in the plugged sebaceous follicle. Two types of true scars exist:

(1) Depressed areas like in pitted acne scarring, and

(2) Raised thickened tissue like in keloids.

When a lesion happens the body sends in the 'troops' to repair the damage. However, when their job is complete they may leave behind a chaos 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 result may be an acne scar.