Hair loss has a huge impact on person’s well-being and self-esteem.  Female pattern hair loss (FPHL) or androgenetic alopecia is the most common form of non-scarring hair loss that primarily occurs in adult women. The condition is characterized by the progressive loss of terminal hairs over the frontal and vertex regions of the scalp, resulting in a visible reduction in hair density. Unlike many cases of androgenetic alopecia in men (male pattern hair loss), the frontal hairline is often spared.

Androgenetic alopecia is a very common condition. The prevalence of female pattern hair loss in Caucasian women is about 19 percent. Although FPHL can occur at any time in life beginning in puberty, the condition most commonly occurs following menopause as approximately 38 percent of women over the age of 70 years have FPHL.

The visible thinning of hair over the frontal scalp and vertex of the scalp in FPHL results from a progressive decrease in the ratio of terminal hairs to shorter, thinner vellus hairs in the affected areas, a process known as follicular miniaturization.  As part of this process, the duration of the anagen (growth) phase of hair follicles shortens from a normal duration of a few years to only weeks to months. The mechanism of follicular transformation that occurs in FPHL is not completely understood. Androgens and genetic susceptibility do play a critical role.

Androgens — androgenetic alopecia occurs as a consequence of the effects of dihydrotestosterone (a potent metabolite of testosterone) on susceptible hair follicles. Dihydrotestosterone binds to androgen receptors in hair follicles, resulting in the up regulation of genes responsible for the gradual transformation of terminal hair follicles to miniaturized hair follicles.

It is polygenetic ie. multiple genes from both sides of the families contribute to the symptoms. Occasionally, hair loss can be caused by hormone imbalance or polycystic ovarian syndrome (PCOS).

It is important to distinguish female pattern baldness from another form of hair loss common in women called telogen effluvium. The pattern of telogen effluvium is usually hair loss that is all over the scalp. This usually occurs more suddenly, possibly 3-8 months after a major stressor (illness, hospitalization, childbirth or death in the family). Other causes of telogen effluvium include medications, thyroid disorders and low iron stores.