Acne is a skin disease often characterized by inflammation in the skin, erupting in lesions. Acne is widespread, particularly during adolescence, and the majority of people experience acne at some point during their life. There are many myths about what causes and cures acne, and an enormous industry has built up around products intended to help prevent and treat acne, especially in teenagers.

To understand acne, it’s important to understand at least basically what a hair follicle looks like. The follicle is buried in the skin, and a hair grows out of it, breaking the skin surface. Attached to the follicle are sebaceous glands, which produce an oil, called sebum, that helps keep skin healthy. Acne occurs when for whatever reason that hair follicle gets blocked and the sebum builds up under the skin. In that rich environment, bacteria start to grow, eventually causing acne.

Although many people think of acne only as the erupted, red form of acne often referred to as a zit or pimple, acne also includes some non-inflamed forms, known as comedones. Acne comedones come in two forms: whiteheads and blackheads. A whitehead is formed when the mass of bacteria and sebum formed by a blocked follicle stay underneath the surface of the skin, and can be extremely small, sometimes even invisible to the eye. A blackhead is formed when the erupted mass is open to the surface, allowing the melanin in the trapped sebum to oxidize and become black.

Ideally, these non-inflamed forms of acne eventually drain the built up sebum and bacteria to the surface and the skin heals. Often, however, the interior wall of the follicle ruptures either because of internal pressure or, more commonly, because of picking at the skin. Once this happens, white blood cells flood into the already engorged follicle to battle the bacteria, and the acne becomes inflamed in what is called a papule.

At this point, the acne is still largely below the skin, and although it is visible to the naked eye, it is more as an angry section of skin than as what most people call a pimple. The pimple of acne forms when the white blood cells doing battle with the bacteria make their way to the surface of the skin, erupting into a large white or whitish-yellow lump. Truly severe cases of acne can lead to extreme inflammation in the form of cysts or nodules as well.

Acne isn’t entirely understood, but it is thought by most people that diet actually has little to nothing to do with its development. Traditionally, many people believed that certain foods, such as greasy foods or chocolate, caused acne, but most studies have shown this not to be the case. Treating acne can be done with any number of lotions and creams, mostly containing benzoyl peroxide or salicylic acid, but one of the best ways to treat acne is simply to regularly wash your face with warm water and a very mild soap, reducing the amount of oil on the skin that can build up and cause blockage.