Blocked pores and follicles

Although you may not notice it, your face is covered with tiny hair follicles.  Your sebaceous glands are constantly producing oil to lubricate the hair and lining of these follicles.  The oil coats the inner lining of the follicle, the hair and even the surrounding skin.  But sometimes oil gets trapped in the follicle.  Sebum oil can get trapped for a number of reasons.  There can simply be too much for the follicle to secrete, or the oil may combine with foreign particulate like dirt or the hair.  It can mix with "scale", the skin cells that are found on the inside of the hair follicle shaft. 

When oil gets stuck in the hair follicle it combines with the scale from dead skin cells. The combination of the oil and dead skin cells form clumps that cause the hair follicle to close up altogether. The surrounding tissues of the closed pores then become irritated, anaerobic (without oxygen) bacteria multiply, and swelling and infection occur.  As the cells shed and oil continues to build up the pimple can form a closed comedone (whitehead) or open comedone (blackhead).

There are a number of different ways to prevent blocked pores from occurring.  First, oil production can be modified.  This can be done with prescription medication or lasers.  Secondly, scale and dirt that combine with the oil to form the blockage must be controlled.  Usually cleansing and exfoliating properly controls dirt and scale buildup.