For people concerned about hair loss, many myths and half-truths abound, but useful information can be difficult to put your hands on. Therefore, an objective overview of pattern hair loss is desirable.  

In healthy well-nourished males and females the most common form of hair loss is androgenetic alopecia (AGA), also known as pattern hair loss. The disorder affects approximately 40 million American men.  It may be a shock to learn that common pattern hair loss affects 20 million American women. The difference between the genders is that a woman suffering hair loss usually retains her juvenile hairline but experiences loss of density behind the leading edge. In men, a distinct pattern manifests where the frontal hair line recedes at the same time that a thinning zone expands from the posterior crown. In more pronounced cases, these zones meet and the person is said to be clinically bald.