During puberty, elevated hormone levels stimulate sebaceous glands to produce more oil (Sebum), which is normally released through the hair shaft to lubricate and protect the skin. Sebum combines with dead cells, forming a plug in the skin pore called a comedone. These comedones or plugged follicles eventually rupture and sebum seeps into the surrounding skin causing inflammation. There are harmless bacteria present in the sebaceous glands. These bacteria break down the fatty parts of the sebum into fatty acid substances which leak into the surrounding of the skin and cause inflammation. The result can be a small or large solid bump or a pustule on the surface of the skin or cysts underneath the surface of the skin.
The symptoms of acne are:
- Whiteheads, which are closed plugged oil glands.
- Blackheads, which are open plugged oil glands (the oil turns black when it's exposed to the air).
- Pustules, which are red, inflamed, infected plugged oil glands, sometimes filled with pus.
- Some pimples may be painful. In severe cases, Cysts (large fluid-filled bumps) may develop under the skin.