Diffuse shedding after rapid weight loss, severe calorie restriction or inadequate nutrition.
Crash dieting can trigger telogen effluvium because the body prioritises essential functions over hair growth during periods of nutritional stress. Shedding may begin two to three months after rapid weight loss or severe dietary restriction. The pattern is usually diffuse rather than patchy. Recovery depends on correcting the trigger and ensuring adequate protein, iron and overall nutrition. Crash dieting can also reveal pre-existing androgenetic alopecia by reducing the margin of visible density.
NHS hair loss: https://www.nhs.uk/symptoms/hair-loss/ ; DermNet telogen effluvium: https://dermnetnz.org/topics/telogen-effluvium
