Blackheads, otherwise known as comedones, occur when the skin becomes congested. Congested skin is caused by a number of variables, which include having naturally oily skin, having a poor diet or becoming stressed. The telltale open pores with black dots happen when bacteria and oil are mixed under the skin, making the area inflamed. As the skin over the spot breaks, the trapped oil and bacteria become oxidised and turn black.
Many people suffer with blackheads at some point in life. There is a well-researched link between heightened stress levels and the appearance of more blackheads. When a person is stressed, the production of the 'stress hormone' cortisol also increases; this in turn augments the production of sebum or oil, making blackheads (and acne generally) significantly more likely.
Another common cause of blackheads and congested skin is eating a poor diet - especially too much dairy and carbohydrates, and not enough green vegetables and fruits (especially berries). Adding more green vegetables, like broccoli and spinach, and fruits high in antioxidants, such as blueberries, strawberries or currants, will strengthen the skin's ability to fight infection and heal itself.
Another effective way to rid yourself of a blackhead breakout is by maintaining a good skincare regime that removes makeup, surface dirt, and dead skin cells.