Telogen Effluvium: Hair Shedding After Illness, Stress, Childbirth or Diet

Finding clumps of hair in the shower drain a few months after a bad flu, a hospital stay or the birth of a baby is alarming. A common explanation is telogen effluvium, a temporary form of shedding. DermNet describes it as a non-scarring, diffuse hair loss that follows a shock to the body, with new hair continuing to grow underneath. This guide covers why it happens, how long it usually lasts, when hair comes back and what a doctor may check.

What happens in the hair cycle

Each scalp hair goes through a growing phase (anagen) and a resting phase (telogen), after which it falls out and is replaced. DermNet explains that normally about 85% of scalp follicles are in the growing phase and about 15% are resting. After a trigger, a large share of growing hairs can switch into the resting phase at the same time. Those hairs then fall out together a few months later, which is why the shedding seems to arrive long after the event that caused it.

Some daily shedding is normal. The AAD and the NHS both put normal loss at 50 to 100 hairs a day. Cleveland Clinic notes that people with telogen effluvium can lose up to 300 hairs a day.

Common triggers

The AAD, DermNet and Cleveland Clinic list similar triggers:

Illness: high fever, severe infection or recovery from a serious illness
Childbirth: shedding after pregnancy is one of the most familiar forms
Surgery or injury: major operations and accidents
Psychological stress: a period of intense emotional strain
Diet and weight loss: the AAD mentions losing 20 pounds or more, and Cleveland Clinic mentions fad diets that lack protein; DermNet adds nutritional deficiency such as low iron
Thyroid disorders: both underactive and overactive thyroid
Stopping the contraceptive pill
Some medicines: Cleveland Clinic names retinoids, beta-blockers, calcium channel blockers, antidepressants and NSAIDs

The Indian expert consensus in the International Journal of Trichology notes that no trigger can be found in nearly one-third of cases.

Hand holding an orange comb with a small clump of hair caught in its teeth, against an apricot background — Normal loss is put at 50 to 100 hairs a day. With telogen effluvium it can reach 300. Photo: Towfiqu barbhuiya / Pexels

Timeline: when it starts and when it stops

The delay between trigger and shedding is the most useful clue. The sources agree on a broadly similar pattern.

Stage	Typical timing	Source
Shedding begins	About 2 to 4 months after the trigger	DermNet; Cleveland Clinic gives 2 to 3 months
After childbirth	Starts around 2 months, peaks around 4 months	AAD
Active shedding	Usually 3 to 6 months	Cleveland Clinic
Back to normal fullness	Usually 6 to 9 months	AAD; DermNet
Chronic form	Shedding lasting more than 6 months	Cleveland Clinic; expert consensus

The AAD adds that shedding can last longer if the stressor continues, especially with ongoing chronic stress. The expert consensus notes that shedding may continue, to a lesser degree, for up to six months after the trigger is removed, and that significant regrowth can take more than a year.

Acute and chronic telogen effluvium

Cleveland Clinic separates acute cases, which last fewer than six months, from chronic cases, which last longer, affect the whole scalp and may have no clear cause. Chronic telogen effluvium is more likely in women aged 30 to 60. Cleveland Clinic reports that about 95% of acute cases resolve.

Woman in a bathrobe parting her hair with her fingers to look at her roots in a mirror — Thinning tends to spread across the whole scalp rather than leaving bald patches. Photo: Karola G / Pexels

How it looks

DermNet and Cleveland Clinic describe:

Thinning spread across the whole scalp, often most visible on top, with no complete bald patches
More hair than usual in brushes, drains and on pillows
Short, fine new hairs along the hairline as regrowth begins
A healthy-looking scalp

That last point matters. Cleveland Clinic notes that the scalp in telogen effluvium is usually free of rash, itching, burning, pain and flaking. If the scalp is red, itchy or flaky, another condition may be involved.

Doctor writing on a clipboard across a desk from a patient — A doctor will ask about illness, stress, diet and medicines in the months before shedding began. Photo: Vitaly Gariev / Pexels

How doctors diagnose it

Diagnosis is usually clinical. Cleveland Clinic describes a scalp exam and a pull test, in which a clinician gently tugs a group of 40 to 60 hairs. If four to six hairs come out with white bulbs at the roots, that points to telogen effluvium. The clinician will also ask about diet, medicines and any illness or stress about three months before the shedding started. DermNet adds that a trichogram, a closer look at plucked hairs, showing more than 25% resting hairs strongly suggests the condition. A scalp biopsy is rarely needed.

Blood tests a doctor may order

Practice varies, and the evidence is mixed.

The expert consensus recommends a basic set for anyone with diffuse hair loss: a complete blood count, a urine test, vitamin D and thyroid function. It lists further tests for when the history points to a specific problem, including iron studies with ferritin, vitamin B12, zinc, calcium, serum proteins and hormone tests.
Cleveland Clinic says testing is usually unnecessary and that blood tests or a biopsy are recommended when a provider suspects an underlying condition.
A 2026 analysis in JAAD International compared 26 blood tests in more than 13,000 women with telogen effluvium against matched controls and found that no test helped identify the cause. The authors suggest testing when there are specific symptoms, such as thyroid concerns or weight change, and discourage routine testing when the rest of the health review is normal.

Taken together, these sources point toward tests chosen to match a person's symptoms and history.

Treatment and recovery

There is no single treatment because telogen effluvium is a reaction to something else. DermNet and Cleveland Clinic focus on finding and addressing the cause, whether that is a thyroid problem, a nutritional gap or a medicine. The expert consensus suggests changing a suspected drug for at least three months, with a doctor's guidance.

Other measures from these sources:

Gentle handling: DermNet advises avoiding vigorous combing, brushing and scalp massage while shedding is active.
Diet: a nutritious diet with enough protein, fruit and vegetables.
Minoxidil: Cleveland Clinic lists over-the-counter minoxidil as an option, while noting it should be avoided during pregnancy or breastfeeding.
Camouflage: hairstyles, wigs or hair weaves while hair regrows.

The outlook is good. Cleveland Clinic says hair usually regrows without treatment, and the NHS notes that hair loss caused by a medical condition usually stops or grows back once the condition is treated. DermNet adds two caveats: recovery may be incomplete, and repeated episodes can sometimes develop into female pattern hair loss.

When to see a doctor

The AAD recommends seeing a dermatologist if you are worried about how much hair you are losing, since some people have shedding and another type of hair loss at the same time. The NHS suggests a non-urgent GP visit for the same reason, and advises seeing a GP before going to a commercial hair clinic.