The most common cause of men's hair loss is androgenetic alopecia – most commonly known as male pattern baldness because it commonly effects men (although there is a female variation of the condition). There are many competing theories on the causes of androgenetic alopecia: some claim it is a genetic condition and others argue that environmental causes play a part in it. Androgenetic alopecia occurs when the cells in a hair follicle fail to duplicate, stopping the hair growing and leaving it weak, to the point where there is no hair left. As of yet, no one can be certain of the causes.
Androgenetic Alopecia often starts with a receding hair line. It rarely leads to complete hair loss, and the variation between hair loss levels is great - while some men will only notice a touch of thinning hair at the temples, some will only be left with a small 'rim' of hair outlining the crown. The condition often affects older men, but this is not exclusive. Depending on the extent of hair loss, there are a variety of pieces available. There are partial pieces for when the hair loss is minimal, and full hair systems for when a great area is affected.