Most people have been troubled by acne at some stage of their lives. The most common form of acne is called ?acne vulgaris? and is caused when the pores of the skin become partially blocked by oil and dead skin cells. Bacteria that is normally found on the skin surface then invades the area, causing inflammation and pain. In many cases the ensuing pimples contain pus and sometimes a blackhead. The blackhead is not dirt, but a change in the pigment of the blockage.

Acne is thought to be partly hereditary, but there are several other factors that can precede its onset. One of these is hormonal activity such as the menstrual cycle. Stress is also likely to bring on the dreaded zits due to increased output of hormones from the stress glands. Anabolic steroids have a similar effect, while medication containing halogens, lithium, barbiturates or androgens is also cited as a cause. A more severe form of acne called Chloracne is caused by exposure to high levels of chlorine. This type of acne is very severe and long lasting.

The normal form of acne usually gets better by itself, but the trouble is that it can often take a long time: decades in some cases. Another problem is that acne at its worst can cause bad scarring of the skin. If a pimple full of pus is squeezed until it bleeds, there will often be scarring.

Some experts say that pimples should not be squeezed because this can force the pus deeper into the skin. This deep-rooted infection can result in scarring and cyst formation. It is easier to prevent these scars in the first place than to cure them, so go easy on the squeezing. If you do squeeze a pimple, wash your hands in a disinfectant first, then gently pierce the pus-filled pimple with a sterile needle. This will allow the pus to come out instead of being forced downwards. Sterilize the needle by passing it through a candle flame two or three times.

Some mature women have what they think is acne, but it may be the less common acne rosacea. It is similar to look at, but the skin is usually flushed and becomes thickened. People who blush easily are the most likely to develop this condition. Acne rosacea is frequently stress-related and is a potential threat to the vision, so a correct diagnosis is imperative. It is possible for the two forms of acne to co-exist. Another condition that can be mistaken for acne is keratosis pilaris.