What is Androgenetic Alopecia?

Androgenetic alopecia, also known as male or female pattern hair loss, is the most common form of progressive hair loss. It affects roughly 70% of men and 40% of women at some point in their lives.

Androgenetic alopecia is an inherited condition caused by a genetically determined sensitivity to the effects of dihydrotestosterone (DHT) to some areas of the scalp.

The genes can be inherited from either parent. DHT causes scalp hair loss by inducing a change in the hair follicles, known as follicular miniaturisation. During each growth cycle the hairs become progressively shorter, finer and lighter in colour. Also the time between shedding of the hair and the new anagen regrowth becomes longer leading to a reduction in the hair present on the scalp, such that eventually the follicles stop producing hair altogether.

Androgenetic alopecia may start at any age after puberty. The progression of androgenic alopecia varies from individual to individual, but usually it is a gradual process which accelerates as one ages. The development largely depends on the hair follicle’s sensitivity  to androgens and the availability of androgens. Females who are losing their hair with age are more likely to present with female pattern loss, in which hormone tests are normal but they have follicular sensitivity to androgens.

Male pattern hair loss generally shows as frontal ‘M’ shaped recession of the hair line with thinning to the vertex area. Female pattern hair loss is characterised by diffuse thinning of the crown with complete or near complete preservation of the frontal fringe. There are, of course, individual variations on these patterns.

There is no cure for androgenetic hair loss but there are licensed and unlicensed treatments that will, in some cases, slow the progression of the hair loss. Licensed treatments include topical minoxidil and, for men, finasteride (Propecia) tablets.