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.
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.
The word acne comes from the word acme meaning "the highest point", which comes from the Greek akme meaning "point" or "spot" - it was originally misspell, with an 'n' rather than an 'm' in 1835.
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.
Dermatologists (skin specialists) say that approximately three-quarters of 11 to 30 year-olds will get acne at some time. Acne can affect people of all races and all ages. It most commonly affects adolescents and young adults, although there are people in their fifties who still get acne.
Although acne affects both men and women, young men suffer from acne for longer - probably because testosterone, which is present in higher quantities in young men, can make acne worse.
Nobody is completely sure what causes acne. Experts believe the primary cause is a rise in androgen levels - androgen is a type of hormone. Androgen levels rise when a human becomes an adolescent. Rising androgen levels make the oil glands under your skin grow; the enlarged gland produces more oil. Excessive sebum can break down cellular walls in your pores, causing bacteria to grow.
Some studies indicate that susceptibility to acne could also be genetic. Some medications which contain androgen and lithium may cause acne. Greasy cosmetics may cause acne in some susceptible people. Hormone changes during pregnancy may cause acne to either develop for the first time, or to recur.