Understanding Acne


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This section aims to provide you with a detailed and comprehensive explanation of why people get acne. Acne appears thanks to a complicated set of circumstances in the skin and the best way to thoroughly understand the condition is to understand each element of the condition.

Sebaceous Glands and Sebum

The key culprits which cause acne are the sebaceous glands. Except from the palms of your hands and the soles of your feet, your entire skin is full of sebaceous glands, the highest density of these glands (almost three thousand per square inch in fact) is found in the skin of your face. When they function correctly the sebaceous glands are thought to keep the skin lubricated. This lubrication removes dead skin cells and stops the skin from becoming dry. The glands do this by producing their own oil known as sebum, which is a natural oil, made from fat, wax and dead skin cells. Sebum travels from the sebaceous glands along ducts in the skin and is eventually end up on the surface of the face after going through the sweat pores.


The sebaceous glands can cause trouble, however, when they become overactive. This means that the glands are overstimulated and produce more sebum than normal. Many factors can cause sebaceous glands to overact, in teenagers the increase of the male sex hormone, androgen, which affects both girls and boys, can trigger the glands to increase the production of sebum. While the factors that can cause the overproduction of sebum are not fully understood other possible reasons include:

  • Nutrition
  • Stress
  • Medications
  • Environment

When too much sebum is produced it clogs the sweat pores that the oil is supposed to escape through. When this clogging occurs the blocked pores can collect dead skin cells, dirt and, most importantly, bacteria.

Blackheads & Whiteheads

A clogged or blocked pore of this kind is known as a comedone. If a pore becomes clogged but does not come in contact with bacteria it forms either an open comedone (a blackhead) or a closed comedone (a whitehead).

Most people believe that the black colour visible in blackheads is dirt trapped in a pore but this is not the case. Instead, the darkness of a blackhead is caused by a tanning chemical called melanin which exists in sebum. When the sebum reaches the surface of the skin but becomes blocked it is exposed to air and sunlight which triggers the melanin to oxidise or ‘tan’. This turns the sebum trapped on the surface of the skin black or very dark brown, resulting in a blackhead.

Whiteheads, meanwhile, form in exactly the same way as blackheads except the sebum gets trapped just below the surface of the skin with only a tiny route to the surface of the skin. This means the melanin in the sebum cannot oxidise or escape. This is why the comedone remains white and slightly raised.

Acne and Bacteria

Propionbacterium acnes is a bacteria that lives naturally in the skin and feeds on sebum. When sebum is overproduced it creates a feast for the bacteria and so the number of propionbacterium acnes increases. Meanwhile, defensive white blood cells are alerted by the presence of so much bacteria and race to the follicles in the skin in order to get rid of the bacteria. In order to fight off the bacteria the white blood cells release an enzyme that damages the follicle in which the sebaceous gland is located. This means that the contents of the follicle can get further into the skin. This spreads the bacteria and sebum and results in inflammations. These inflammations are commonly knows as spots, zits or pimples but are in fact inflamed comedones of which there are at least four types: papules, pustules, nodules and cysts.


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