Condition

Telogen Effluvium

Telogen effluvium is a heavy, all-over shed that begins two to three months after something stressed the body - an illness, an operation, childbirth, a crash diet or a new medicine. The follicles are not damaged, so in most people the hair grows back on its own.
Dr. Schwarz, MD · Board-certified dermatologistLast reviewed September 8, 2026
16:9 hero for Telogen Effluvium. Never cropped: the tone strip and the corner logo depend on the full frame.

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The most useful thing I do in the room is a calendar. Hair sheds on a delay, so whatever caused this happened two to three months ago, not last week, and finding it usually solves the whole mystery. This is not going bald - the follicle is intact and the new hair is already growing while the old one is still coming out, which is why I spend part of the visit looking for short new hairs along the hairline. Shedding in handfuls every day is frightening even when the outcome is good, so it is fair to want it looked at and fair to want blood tests, because a treatable trigger like low iron or an underactive thyroid turns up often enough to check.

— Dr. Schwarz, Board Certified Dermatologist

Key Facts

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How commonVery common - the usual reason for sudden heavy shedding all over the scalp
Who gets itAnyone. Reported more often in women, partly because pregnancy, restrictive dieting and low iron are common triggers
Curable or managedUsually self-limiting. It stops on its own once the trigger has passed, and the follicles are not damaged
Prescription neededNo. Blood tests are often worth doing to find a trigger that can be corrected
Time to improveShedding usually settles within three to six months. Density takes six to twelve months to look normal again

What It Is

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Every hair follicle cycles between a long growing phase and a short resting phase. A resting hair stays anchored about three months, then releases as the new hair beneath it starts to grow - the ordinary shedding everyone does, usually 50 to 100 hairs a day.

Telogen effluvium is a large number of follicles pushed into the resting phase at once. Something stresses the body - a high fever, an operation, childbirth, rapid weight loss, a new medicine, an untreated thyroid problem - and many growing follicles cut their growth short and switch to resting together. Nothing shows at that point. Two to three months later those hairs release together, and the shedding is sudden, heavy and all over the scalp rather than in patches.

The follicle is undamaged throughout, which is the point of the diagnosis. It starts a new hair immediately, so recovery is underway on the day the shedding starts. The hair thins because so much is coming out at once, not because follicles are lost.

Pattern hair loss is different - slow thinning of individual hairs in a set pattern, no dramatic shed - and so is alopecia areata, which makes smooth bald patches. A heavy shed often reveals pattern thinning that had been developing quietly for years.

Symptoms

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Handfuls of hair

Sudden Shedding

A noticeable increase in shedding, seen in the shower and on the pillow, typically two to three months after a trigger such as illness, surgery, childbirth, weight loss or severe stress. Hair comes out from the root rather than breaking. The delay is why the cause is often missed.
Even thinning all over

Diffuse Thinning

Thinning spread evenly across the whole scalp rather than in patches or in a pattern, so the ponytail feels thinner. The hairline usually stays intact. It generally recovers over six to nine months once the trigger has passed.
Months of loss

Ongoing Shedding

Shedding that carries on beyond six months, which suggests the trigger is still present, such as a thyroid problem, low iron, a medicine or ongoing illness. Blood tests are usually part of sorting this out. It can also unmask pattern hair loss.

Where It Shows Up

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Front view of a head with red marks spread evenly across the whole scalp, including the sides. The front hairline is clear.
The whole scalp at once
The shedding is spread across the whole scalp, so the top, the sides and the back all thin at the same time. The front hairline usually stays where it was. Hair coming out in patches, or only at the edges or the crown, points to a different condition rather than a simple shed.

What Happens in the Skin

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This is what is going wrong under the skin, in the order it happens. Click a step to see it.

How Telogen Effluvium happens
Skin basics
BARRIEREPIDERMISDERMISHAIRSIGNAL0NORMAL HAIR CYCLE1SOMETHING STRESSES THE BODY2FOLLICLES SWITCH TO RESTING TOGETHER3THE DELAYED SHED4THE FOLLICLE RESTARTS

Each follicle spends years growing a hair, then rests for about three months and releases it as a new hair pushes up underneath. Follicles do this out of step with one another, so only a small share are resting at any moment. That is why ordinary shedding is spread thin, roughly 50 to 100 hairs a day.

A high fever, an operation, childbirth, a fast weight loss, low iron, a thyroid problem or a new medicine puts the body under strain, and hair is one of the first things it treats as optional. Nothing shows on the scalp on the day it happens.

A large share of growing follicles cut the growth phase short and move into the resting phase at the same time. The hairs stay anchored where they are, so the hair looks and feels exactly as it did.

Two to three months later, all of those resting hairs release together. That is the sudden heavy shedding, and it is the first thing anyone notices, a whole season after the event that caused it.

The follicle was never damaged, so it begins a new hair as soon as it lets the old one go. Regrowth is already underway on the day the shedding starts, and short new hairs appear along the hairline over the following months. Everything on the lists below is either protecting this step or keeping the trigger going.

The outer film of dead cells and oil. It holds water in and keeps irritants out, and it is thinner than a sheet of paper. Almost every dry, itchy, stinging skin problem starts here.

The outer layer, and the only one anything in a jar reaches. It renews itself constantly: a cell made at the bottom takes about a month to reach the surface and flake off. Most of what a skincare product does, it does here.

The living layer underneath, holding the blood vessels, the nerves and the collagen. It is where lasting change happens and it is hard to reach: most of what is sold for the skin never gets this far.

Four things happen in order, separated by the delay that makes this confusing. First comes the trigger - a high fever, an operation, childbirth, rapid weight loss, a new medicine, or an untreated thyroid or iron problem (1). Second, a large share of follicles cut their growth phase short and shift into resting together, invisibly (2). Third, two to three months later, those hairs release together - the shed you notice (3). Fourth, the follicle - never damaged - starts a new hair, so regrowth begins as the shedding starts and short new hairs appear along the hairline over the following months (4).

The delay is the part to hold on to - the scalp is reacting to something that happened a season ago, not to what you did yesterday or the shampoo you bought last week.

The common triggers are a severe illness with a high fever, surgery, childbirth, a crash diet or large rapid weight loss, iron deficiency, an over- or underactive thyroid, a major emotional shock such as a bereavement, and starting or stopping certain medicines. Often more than one applies. Sometimes no trigger is ever found, and the hair still recovers.

Risk Factors

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Anyone can get telogen effluvium, since the trigger is usually a one-off event rather than a trait. Knowing them in advance means a shed three months later is not a shock.

Physical stress
Recent childbirth
Very common. Pregnancy keeps hairs growing longer, and the drop after delivery releases them together, usually two to four months later.
Physical stress
Severe illness or a high fever
Including major infections and hospital stays. The shed follows about three months later, when you feel well again.
Physical stress
Surgery and general anesthetic
A common trigger, usually forgotten by the time the shedding starts.
Nutrition & weight
Rapid weight loss and restrictive dieting
Very low calorie or protein intake and bariatric surgery all trigger it. The body deprioritizes hair.
Nutrition & weight
Iron deficiency
Common, very correctable, and often present without full anemia. Worth measuring rather than assuming.
Other health conditions
Thyroid disease
Overactive and underactive both cause shedding, and both are treatable.
Other health conditions
Certain medicines
Blood pressure medicines, blood thinners, retinoids and antidepressants among others. Never stop one on your own - ask your doctor.
Emotional stress
Major emotional stress
Bereavement, a serious accident or extreme strain can trigger it, on the same delay.

Course

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The pattern is reassuring - a trigger, a long delay, a heavy shed, then recovery. Shedding past six months is chronic telogen effluvium, which should be reassessed, not waited out.

The delayFirst 2-3 months
Nothing has changed yet

Shedding begins about two to three months after the trigger. Until then the hair looks the same, so the shed seems to come from nowhere.

Heavy sheddingRoughly 2-3 months
The shed peaks

Shedding ramps up over a few weeks, then stays heavy for two to three months. Most people shed several hundred hairs a day at the peak, worst on wash days.

Regrowth startsBefore the shedding ends
New hair appears while old hair is still falling

The follicle restarts as soon as it releases the old hair. The sign is a fringe of short, fine, wiry hairs that will not lie flat - there before anyone believes things are improving.

HairlinePart line
The shed settlesWithin 3-6 months of starting
The falling stops

Once the trigger is over, shedding settles within three to six months of starting.

Density returns6-12 months of regrowth
Volume takes longer than the shed did

Hair grows about a centimeter a month, so a hair restarting today needs six to twelve months to add volume, longer if your hair is long. Most people are back to normal within a year of the trigger.

What Makes It Better & Worse

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A shed that will not settle almost always means the trigger is still there.

What is driving yours?

FATHAIRSIGNALBARRIEREPIDERMISDERMIS

A high fever, an operation, childbirth, a fast weight loss, low iron, a thyroid problem or a new medicine puts the body under strain, and hair is one of the first things it treats as optional. Nothing shows on the scalp on the day it happens.

A large share of growing follicles cut the growth phase short and move into the resting phase at the same time. The hairs stay anchored where they are, so the hair looks and feels exactly as it did.

Two to three months later, all of those resting hairs release together. That is the sudden heavy shedding, and it is the first thing anyone notices, a whole season after the event that caused it.

The follicle was never damaged, so it begins a new hair as soon as it lets the old one go. Regrowth is already underway on the day the shedding starts, and short new hairs appear along the hairline over the following months. Everything on the lists below is either protecting this step or keeping the trigger going.

What helps

  • Find the trigger and deal with it Look back two to three months from when the shedding started, not two to three weeks.
  • Get the standard blood tests Iron stores, thyroid function and a full blood count, sometimes vitamin D.
  • Correct iron deficiency if you have it Iron helps when ferritin is low and harms when it is not, so test first.
  • Treat a thyroid problem Shedding settles once levels are back in range.
  • Eat enough, and eat enough protein Normal calories and protein at each meal remove the signal.
  • Ask the prescriber first Swapping a suspected medicine is their decision.

What makes it worse

  • Crash dieting A very common trigger, and a common reason a shed keeps going.
  • Not enough protein Hair is mostly protein, and the body treats it as optional.
  • Untreated iron deficiency Easy to test for, and it prolongs shedding until corrected.
  • An untreated thyroid problem Underactive and overactive both keep the shedding going.
  • Repeated or continuing illness Each new fever, infection or operation can start another wave.
  • Prolonged emotional stress Months of it keep the process going.
  • Starting and stopping medicines Both directions can trigger a shed, including hormonal contraceptives.

What helps

  • Give it time Shedding settles within three to six months once the trigger is gone.

What makes it worse

  • Switching products every few weeks It does nothing to the cycle, and means more washing and heat.
  • Counting hairs every day Daily counts mostly measure your wash schedule.

What helps

  • Handle the hair gently while it recovers New hairs are short, fine and easy to snap.
  • Topical minoxidil, sometimes Occasionally used to support regrowth, though the evidence is thin.
  • Look for the short hairs A fringe of new growth along the hairline means the follicles are working.

How These Treatments Work

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Treatments for Telogen Effluvium do not all work in the same place. Tap one to see where it acts.

Pick a treatment
Skin basics
BARRIEREPIDERMISDERMISHAIRSIGNALREMOVES THE CAUSEFIXES THE SUPPLYWAKES THE FOLLICLE UPTHE CYCLE RESETS

Illness, surgery, birth, weight loss or stress pushed many follicles into rest at once, about three months ago.

The two checks worth doing in almost everyone with this.

Optional. It may shorten the wait, but most people recover without it.

Follicles that shed together regrow together, over six to twelve months.

The outer film of dead cells and oil. It holds water in and keeps irritants out, and it is thinner than a sheet of paper. Almost every dry, itchy, stinging skin problem starts here.

The outer layer, and the only one anything in a jar reaches. It renews itself constantly: a cell made at the bottom takes about a month to reach the surface and flake off. Most of what a skincare product does, it does here.

The living layer underneath, holding the blood vessels, the nerves and the collagen. It is where lasting change happens and it is hard to reach: most of what is sold for the skin never gets this far.

Over-the-Counter Products

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Everything here you can buy without seeing anyone.

Iron, only if a test shows you are low
Iron, only if a test shows you are low
Moderate evidence
Low iron stores are one of the few genuinely correctable triggers, and they are common without full anemia, so they are worth measuring rather than guessing at. When ferritin is low, correcting it settles the shedding over the following months. Iron taken without a deficiency does nothing for hair and is harmful, which makes this a test-first treatment.
A plain white bottle with a gray applicator tip lying on its side, labeled MinoxidilDiagram of a hair follicle in cross-section, labeled to show that minoxidil keeps the follicle in its growing phase for longer.
Limited evidence
Sometimes used to support regrowth, mainly when a shed has dragged on past six months or has uncovered pattern thinning underneath. The evidence in telogen effluvium itself is thin, because the hair was going to regrow anyway. It also causes a short burst of extra shedding in the first few weeks, which is hard to sit through in the middle of a shed.
Biotin and hair supplements
Biotin and hair supplements
Weak evidence
These do nothing for a shed unless you were low in the exact thing they contain, and most people are not. Biotin also interferes with thyroid and heart blood tests, which can send the search for the real trigger off in the wrong direction. If you are going to spend money on this, the blood tests are the better place to put it.

Prescriptions

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These need a prescription.

An amber prescription bottle lying on its side on a white background with a plain white label reading Levothyroxine, and six small round white tablets spilled out in front of it.
Treating a thyroid problem
Strong evidence
When an overactive or underactive thyroid is the trigger, the shedding settles over the months after the levels come back into range, and no separate hair treatment is needed. Both directions cause shedding and both are treatable. This is the clearest example of why the blood tests matter more than anything you can put on the scalp.
An amber prescription bottle lying on its side on a white background with a blank white label and no name on it, and six small round white tablets spilled out in front of it.
Reviewing a suspected medicine
Moderate evidence
A number of common medicines can start a shed, and stopping one can do the same. Some can be swapped easily and others should not be touched, so the decision belongs with the doctor who prescribed it. Take the whole list to that appointment rather than stopping anything yourself to find out.
Diagram of a hair follicle in cross-section, labeled to show that minoxidil keeps the follicle in its growing phase for longer.Diagram: how Oral Minoxidil works in the skin
Limited evidence
A low dose of an old blood pressure tablet, used off-label by dermatologists and sometimes offered when shedding has run well past six months or pattern thinning has been found underneath. It is not a treatment for an ordinary shed, which recovers without it. It needs a prescription and monitoring, and it can cause unwanted hair on the face and body.

Procedures

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These are done in the office, usually over several visits.

16:9 hero for PRP for Hair Loss. Never cropped: the tone strip and the corner logo depend on the full frame.
Weak evidence
Injections of your own concentrated platelets into the scalp, marketed for every kind of hair loss. It has been studied mainly in pattern hair loss rather than in this, and a straightforward shed regrows on its own within the same months a course would run. It is several expensive sessions, so it is worth being clear about what you are buying before you start.

When to See a Dermatologist

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A single shed after an obvious trigger, in someone otherwise well, usually settles on its own. It is still worth coming in, because the blood tests that find a correctable cause are simple and a diagnosis beats an assumption. Book if the shedding has gone on more than six months, if you cannot identify a trigger in the two to three months beforehand, if your part line is visibly widening or the scalp is showing through, if you are losing hair in patches rather than all over, or if the scalp itches, burns, is tender, red or scaly. Book too if you also have fatigue, weight change, heavy periods or a change in how you feel the cold, if the loss began after a new medicine, or if it is affecting your mood - and expect blood tests for iron stores, thyroid function and a full blood count, since several triggers only show up that way.

— Dr. Schwarz, Board Certified Dermatologist

Complications

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Pattern hair loss underneath

A heavy shed can thin the hair enough to uncover pattern hair loss that had been developing quietly for years. The shed itself recovers, and the pattern thinning does not, so density that has not returned about a year after the trigger is worth having looked at rather than waited out. The clue is shape. Pattern loss widens the part at the front while the back of the scalp stays as it was.

Shedding that will not settle

Shedding still going six months on is called chronic telogen effluvium, and it usually means the trigger is still there — low iron, an untreated thyroid problem, a medicine, or one illness after another. The follicles are still undamaged, so this is not the start of baldness. It does need reassessing and blood tests rather than more waiting.

The distress it causes

Watching hair come out in handfuls is frightening, and it changes how people wash, dress and go out long before anyone else notices a difference. That is a real part of this condition and not a small one. The outcome in a straightforward shed is good, but the waiting is hard, and it is fair to ask for help with the worry as well as with the hair.

Lookalikes

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Female Pattern Hair Loss

Both leave the hair thinner, and the two often turn up together, which is why they are confused so often. Pattern hair loss is slow and has a shape — the part widens at the front while the back and sides stay as they were — and there is no dramatic shed. Telogen effluvium is heavy shedding all over, on a two to three month delay, and it grows back.

Alopecia Areata

Alopecia areata takes hair out in smooth, round, completely bare patches with normal-looking skin inside them, usually over a few weeks, and it can appear anywhere including the back and the sides. A telogen shed never leaves a bare patch. It thins everything evenly, and hair keeps growing across the whole scalp while it does.

Male Pattern Hair Loss

Men who suddenly find hair on the pillow usually assume this is the start of going bald. The male pattern is gradual and shaped — the temples move back and the crown hollows out while the back and sides stay thick — and it does not come in a burst. A shed after an illness, an operation or a big weight loss arrives all at once, spares no part of the scalp, and recovers.

Myths

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  • "I am going bald." Telogen effluvium does not cause baldness. The follicles are intact and already regrowing, and even the long-running version does not lead to a bald scalp. A heavy shed can thin the hair enough to reveal pattern hair loss already developing, which is a separate condition with a separate answer.
  • "Washing my hair is making it fall out." Washing releases hairs that had already detached. Washing less often does not reduce the total - it stores them up, so more come out on the day you wash.
  • "It must be something I did last week." The shed follows the trigger by two to three months, so nothing from last week is responsible. That delay is the most useful thing to know, and it saves blaming the wrong thing.
  • "A supplement will stop it." Hair, skin and nail supplements do nothing unless you were deficient in what they contain. Biotin is the clearest example - it helps only genuine biotin deficiency, which is rare, and it interferes with thyroid and cardiac blood tests.
  • "I should cut it short so it grows back stronger." Cutting changes nothing at the follicle. A shorter cut can make thin hair look fuller and remove damaged ends, which is a fine reason to do it, but it does not affect shedding or regrowth.
  • "My hair will never be the same again." Most people return to their previous density within about a year of the trigger. Recovery is slow enough to miss, which is why photographs every few months are more honest than the mirror.

Questions Patients Ask

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How much shedding is normal, and how much is too much?

Most people shed 50 to 100 hairs a day, varying with how recently you washed. Telogen effluvium is usually several hundred a day and, more tellingly, a clear change from your own normal. The change and how long it has lasted matter more than the number.

When will it stop?

Usually within three to six months of starting, provided the trigger has passed. Volume takes longer, six to twelve months, because hair grows about a centimeter a month and has to reach a useful length before it shows.

Will it all grow back?

In a straightforward telogen effluvium, yes - the follicles are undamaged. The exception is a shed that uncovers pattern hair loss underneath. The shed recovers and the pattern thinning does not, which is worth identifying rather than waiting out.

Should I take a hair supplement?

Only for something a blood test showed you are low in. Iron and thyroid are worth checking, and vitamin D is often added. Iron without a deficiency is actively harmful, and biotin does nothing unless you are deficient while interfering with thyroid and heart blood tests.

Could my medicine be causing this?

Possibly - many common medicines can trigger shedding, and so can stopping one. Do not stop anything to find out. Take the list to the prescriber, since some can be swapped easily and others should not be touched.

Is my hair shedding because I am stressed?

A single severe stress, such as a bereavement or serious illness, is a well-recognized trigger, on the same two to three month delay. Ordinary day-to-day stress is a much weaker explanation; if that is the only candidate, look harder for a physical trigger and get bloods done.

References

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