What Causes Common Hair Loss or Baldness?

Q: I know that I am going to be bald because my father is bald and I am losing my hair just like him. What actually causes this kind of hair loss? — J.P., Paradise Valley, Arizona

A: Although there are many different causes, the overwhelming number of people that have hair loss have what is referred to as “patterned hair loss” or “androgenetic alopecia.”

In men, it is due to a hormone called DHT, which is a by-product of testosterone produced by the action of the enzyme 5-alpha reductase. This enzyme is inhibited by the hair loss medication Propecia. See the causes of hair loss in men page on the Bernstein Medical – Center for Hair Restoration website for more information.

In women, the mechanism is a little bit more complex as another enzyme, aromatase, is involved in the metabolic pathway. See the causes of hair loss in women page on the Bernstein Medical – Center for Hair Restoration website for more information.

We know that the inheritance comes from both the mother’s and father’s side, although the actual genes causing hair loss in men and women have not yet been identified. Statistically, the inheritance from the maternal side appears to be a bit stronger, but the reason for this is unknown.