Six hair specialists went through every published study on chronic telogen effluvium, the label used when someone sheds heavily for months and no cause turns up. They were asking a blunt question: is this actually its own condition, or is it a bucket we put people in when we cannot find the answer. Eighteen studies met their criteria, covering 1,628 cases.

What they found was that not one of those studies had ruled out every possible cause of shedding before applying the label. Only three studies followed anyone forward over time, and between them that was eight patients. Every study that took biopsies reported a normal ratio of thick hairs to fine ones, which is the measurement used to separate this from pattern hair loss. Their conclusion is worth reading slowly: many cases currently labeled chronic telogen effluvium are likely either early female pattern hair loss, or shedding from a trigger nobody identified. Some, they add, may be a preoccupation with normal shedding in people with long hair. The authors are direct about their own limits. There is no agreed definition of the condition, the underlying studies are mostly small case series, and 97.5 percent of the published cases are women, which they read as a sign the label gets applied unevenly rather than as a fact about who sheds.

Here's the study: Daunton A, Harries M, Sinclair R, et al. Chronic Telogen Effluvium: Is it a Distinct Condition? A Systematic Review. American Journal of Clinical Dermatology, 2023;24(4):513-520. Read it here

New to this? The Foundation is where you get your vocabulary. It teaches you to take what you're seeing on the scalp, put real words to it, and connect it to what it could be.

That language is what everything else gets built on. You can keep it behind the chair for deeper conversations with your clients, or use it as the ground floor for going further.

Start with the Foundation