Telogen effluvium
A large amount of hair shedding at once, usually two to four months after something the body registered as significant. Frightening to experience, and in most cases self-limiting.
01 What it is
Hair grows in cycles. At any moment most follicles are growing and a minority are resting before releasing the hair. Telogen effluvium happens when an unusually large number of follicles are pushed into the resting phase at the same time. Two to four months later, sometimes longer, they release together, and shedding becomes dramatic.
The delay is the single most confusing thing about it. By the time hair is coming out in handfuls, the event that triggered it has usually been and gone, which is why the cause is so often missed.
In most cases the follicles are intact and the cycle recovers, provided whatever triggered it has resolved. Recovery is measured in months, not weeks.
02 Recognition
What people usually notice
- Hair coming out in the shower, on the pillow, on clothes, in the brush: everywhere, all at once.
- Shedding that is diffuse rather than patchy, across the whole scalp.
- Full-length hairs with a small pale bulb at the root.
- A ponytail that has noticeably reduced in thickness over a few months.
- The scalp itself looking and feeling normal.
- A sense that it started abruptly, on a date you can almost name.
03 Contributors
What may contribute
Grouped by how well supported each one is. That distinction matters more than the list itself.
Well established
- Childbirth, one of the most common and most predictable triggers.
- Significant illness, high fever, surgery, or a period in hospital.
- Rapid or substantial weight loss, restrictive dieting, or under-eating.
- Iron deficiency, and low ferritin even without anaemia in some people.
- Thyroid dysfunction, in either direction.
- Starting or stopping certain medications, including hormonal contraception.
Commonly associated
- Prolonged psychological stress or a period of acute distress.
- Vitamin D insufficiency.
- Recovery from viral illness.
- Major life disruption: bereavement, a move, sustained sleep loss.
Debated or unsupported
- Single-nutrient explanations offered without any testing.
- Blaming a shampoo or a product introduced around the time shedding became visible. The timeline usually rules it out.
04 Uncertainty
What we don’t know
- Why some people shed heavily after a trigger that others meet with no hair change at all.
- Why a minority go on to a chronic form lasting well beyond six months, without an identifiable ongoing cause.
- How much of what is attributed to stress is stress itself, and how much is what stress does to eating, sleeping and general health.
Worth doing first
When to bring a doctor in
- If shedding has continued beyond six months, or has no identifiable trigger.
- To have iron studies including ferritin, thyroid function, and a full blood count done. This is a reasonable request and a good starting point.
- If you also have fatigue, weight change, temperature intolerance, or changes to periods.
- If the scalp is sore, scaly or inflamed, or if you can see patches rather than diffuse loss.
- If it followed a new medication. Do not stop it, but do ask.
If any of this applies, see a doctor first. It’s the quickest way to an answer. Bring what they tell you back to me and we’ll work out what it means for you.
05 Consultation
What a consultation can explore
- A careful reconstruction of the four to six months before shedding began. This is usually where the answer is.
- Medications, supplements and their start dates.
- Nutrition, in practical detail rather than in principle.
- Whether shedding is masking or overlapping with something else, such as an underlying pattern.
- Blood results you already have, and which further ones are worth asking for.
- What is realistic to expect month by month, and how to tell recovery from continued loss.
- How to handle hair during a period when losing more of it is unavoidable.
Most telogen effluvium resolves. That does not make it a small thing to live through, and “it will grow back” is not an explanation.
What happens next
Book
Online, wherever you are. You’ll receive a questionnaire and a prep sheet, and I read both before we meet.
We look at it properly
History, assessment, findings, and time for the questions you came with.
You get it in writing
A summary you can act on, sit with, or hand to your doctor.
This page describes what people commonly experience. Reading it isn’t the same as having someone look at your situation properly, and it can’t tell you which of these you have. That’s what the consultation is for.
Sources and further reading
- DermNet Telogen effluvium
- NHS Hair loss
- American Academy of Dermatology Hair loss: why it happens and what to do
Written by Brigita Deveikaite, certified trichologist (VTCT Skills (ITEC) Level 4 Certificate in Trichology for Hairdressers, Trichocare). Last reviewed . This page is educational and is not a diagnosis.