Bacteria

These little critters worsen the skin condition and enter pores clogged up with dirt to form acne. The bacteria are in a family called Propionibacterium and they love to grow in hair follicles. The bacteria basically infects the follicle, and just like any other infection, causes redness, swelling and pain. The infected follicle eventually bursts the skin surface due to the accumulation of dirt, oil and bacteria, and eventually spreads across the skin surface to create a visually apparent infected acne.

Oil on the skin

Sebaceous glands, similar to sweat glands, produce an oil called sebum that is a natural skin lubricant. During new adolescence, the reason for both the psychological and physical changes to the teenager, is due to the massive alteration in hormonal activity within the body. This shift in hormone levels also stimulates the activity of these sebaceous glands to produce more of this sebum. The oil, because of its excess, can block out the skin pores easily, and along with dirt and bacteria as explained already, can result in the formation of acne.

Dead skin cells:

The build up of dead skin cells can also cause acne on the skin. Similar to plain old dirt or bacteria, these skin cells can clog up the pores on the skin, and along with the bacteria and especially increased oil production in adolescence, increases the chance of acne formation. It is during these years that dead skin cells are removed more rapidly, and therefore lay on the surface of the skin more, which increases its vulnerability to acne.

Diet

It is important to have a healthy diet to prevent the formation of acne. Constituents of a diet that can cause acne include excessive oily or fried food, and chocolate intake. This is an indirect cause of acne, because fried foods can increase body cholesterol, which results in the metabolism of this into oil. Chocolates or sugary foods likewise, can be converted into fat for storage in the body, which will eventually result in the release of more oil from the skin. This is not to say that you cannot eat junk food once in a while, however if you keep fit and exercise regularly, and thus burn off the excess cholesterol and carbohydrates, then you would have less to worry about.

Stress

This is also an indirect cause of acne, and it is simply a results of the psychosomatic effect of stress increasing the stimulation of the sebaceous glands in the skin to produce more oil. It also decreases body immunity and so rendering your body more vulnerable to the infective effects of the bacteria harboring your skin surface.