Female pattern hair loss (FPHL) is a distinctive form of diffuse hair loss that occurs in women with androgenetic alopecia. Many women are affected by FPHL. Around 40% of women by age 50 show signs of hair loss and less than 45% of women reach the age of 80 with a full head of hair.

In FPHL, there is diffuse thinning of hair on the scalp due to increased hair shedding or a reduction in hair volume, or both. It is normal to lose up to 50-100 hairs a day. Another condition called chronic telogen effluvium also presents with increased hair shedding and is often confused with FPHL. It is important to differentiate between these conditions as management for both conditions differ.