There is no consensus on the amount of hair shedding in women that is normal versus that which is excessive and no simple tool to assess hair shedding.
To develop a tool that defines normal and excessive hair loss, 900 long hairs from a woman with FPHL were separated into 6 bundles, photographed and used to create a visual analogue hair shedding scale.
The scale was piloted for usability in 50 women attending a hair loss clinic. Shedding scores were subsequently obtained from 209 women newly diagnosed with female pattern hair loss (FPHL). Normal shedding was defined among a100 adolescent school girls.
In the pilot study, there was strong agreement between scores at week 0 and weeks 2 (r=0.98). Among the 209 consecutive women with previously untreated FPHL, with a mean age of 46.3 and with shoulder length hair , 142 (68%) reported grade 5 or 6 shedding. The mean shedding score was 4.96. Among the100 school girls with a mean age of 13.51 year and no hair loss. 99 girls had shedding scores < 4 and 1 girl had grade 5 shedding. The mean score was 2.68 The difference was 2.28 (p<0.0001).
I consider grades 1-4 shedding normal. Grades 5 and 6 shedding indicate excessive hair shedding. Excessive hair shedding is found in 70% of women with FPHL.