male pattern baldness

Last reviewed 11/2022

Androgenic alopecia (AGA) is a non scarring, progressive miniaturization of the hair follicle which has a characteristic pattern of distribution (1).

  • this is a common disorder affecting genetically predisposed men and women (1)
  • the prevalence increases with age in both sexes (2)
  • genetic factors determine age of onset and severity.

Hair loss is usually insidious, presenting as thinning rather than shedding.

In men

  • tend to lose hair over the crown, along the frontal hair line, and the temples
  • occasionally a female pattern of hair loss can be seen as well (1)
  • type 2 5 alpha-reductase is to believed to be important in the development of male-pattern baldness.

In women

  • hair loss over the frontal and central areas, but the parietal and occipital regions may be involved as well
  • occasionally it may occur in a male pattern as well (1)