It is generally well known that both men and women can suffer significant hair loss.

Having said that it may not , however, be well known that more than 50% of men,at some time in their lives, will suffer with Male Pattern Baldness (MPB.) also known as androgenetic alopecia . There is no evidence at the present time to suggest that this will happen at any particular time in a person's life.

The major reason which accounts for hair loss is a genetically inherited sensitivity to Dihydrotestosterone (DHT) and 5 - alpha- reductase. The enzyme 5 -alpha-reductase actually converts testosterone, a male hormone , to DHT . This is the substance which has been identified as the end cause for hair loss.

There is a general acceptance in the community that most male hair loss follows a pattern which has been codified in a table called the Norwood Scale. This scale has seven patterns of hair, which are identified as follows:

Norwood Scale 1 - This is considered as being a normal head of hair, and consequently has no visible hair loss.

Norwood Scale 2 - This is considered a primary stage of of hair loss, with the hair receding in a wedge shaped pattern from front to back of the head.

Norwood Scale 3 - The hair is still receding in a wedge shaped pattern, but the hairline has now receded farther back into the frontal and the temporal regions.

Norwood Scale 4 - The hair is still receding but is now a lot more severe in the frontal and temporal regions. In addition to the more severe recession of the hairline in the frontal and temporal regions there is hair loss at the very top centre of the head. Generally, however, there will be a bridge of hair which remains between that region and the front.

Norwood Scale 5 - The bridge of hair, between the frontal region and the top centre is also known as the vertex and at this stage the hair in this region will have started to become thin.

Norwood Scale 6 - The hair loss at this stage has become quite severe, and the bridge of hair between the frontal area and the vertex will have disappeared completely.

Norwood Scale 7 - This is the final stage of hair loss. The hair has now receded back to the base of the head, and also to just above the ears on the sides.

It is generally accepted that the Norwood patterns are genetically determined.