Acne

Acne is a disease of hair follicles. The hair follicles produce hair. These hair follicles are attached with sebaceous glands. Hair follicles are located all over the skin except for a few places such as palms, soles and lips.

When the pore opening of the follicle gets blocked by dead skin cells it prevents the sebum going out. As a result, sebum gets collected inside the follicle. These blocked follicles are called blackheads or whiteheads. Blackheads and whiteheads are also known as comedones. A comedone is defined as: a sebaceous follicle that is plugged and filled with sebum, dead cells, etc.