Acne, medically known as Acne Vulgaris, is a skin disease that involves the oil glands at the base of hair follicles. It commonly occurs during puberty when the sebaceous (oil) glands come to life - the glands are stimulated by male hormones produced by the adrenal glands of both males and females.There are various types of pimples: Whiteheads, Blackheads, Papules, Pustules, Nobules, Cysts.
Acne is not dangerous, but can leave skin scars. Human skin has pores (tiny holes) which connect to oil glands located under the skin. The glands are connected to the pores via follicles - small canals. These glands produce Sebum, an oily liquid. The sebum carries dead skin cells through the follicles to the surface of the skin. A small hair grows through the follicle out of the skin. Pimples grow when these follicles get blocked, resulting in an accumulation of oil under the skin. In humans, pimples tend to appear on the face, back, chest, shoulders and neck. Simply put - skin cells, sebum and hair can clump together into a plug, this plug gets infected with bacteria, resulting in a swelling. A pimple starts to develop when the plug begins to break down.