Most people lose somewhere between 50 and 100 hairs a day without ever noticing. Then, sometimes with no obvious warning, the numbers change. The plughole fills up after every shower, the pillow is covered in hairs each morning, and a gentle tug brings away a small bundle instead of one or two strands. For many people the shock comes a few months after an illness, an operation, a new baby or a stressful period they had almost forgotten about.
That delay is what makes this kind of hair loss so confusing, and so frightening. It rarely looks connected to anything, and it can feel as if the hair will never stop falling. In hair restoration it is one of the most common reasons people come for a consultation, and one of the most important to recognise, because it behaves very differently from the hair loss that a transplant is designed to treat.
Telogen Effluvium at a Glance
Telogen effluvium is a temporary, diffuse shedding of hair that happens when a large number of growing hairs switch into the resting (telogen) phase at the same time, usually two to three months after a trigger such as illness, high fever, surgery, childbirth, rapid weight loss or severe stress. The follicles are not damaged, so the hair normally grows back within six to twelve months once the trigger has passed. Unlike male or female pattern hair loss, it affects the whole scalp evenly and does not cause permanent bald areas.
How does telogen effluvium happen?
What are the phases of the hair cycle?
Every hair follicle goes through the same cycle, independently of its neighbours:
| Phase | What happens | How long it lasts |
|---|---|---|
| Anagen (growth) | The hair actively grows | Two to six years on the scalp |
| Catagen (transition) | Growth stops and the follicle shrinks back | About two to three weeks |
| Telogen (resting) | The hair stays in place but no longer grows | About three months |
| Exogen (shedding) | The resting hair falls out as a new one starts | Part of the end of telogen |
On a healthy scalp, roughly 85–90% of hairs are growing and around 10–15% are resting at any time. Because the follicles are out of step with each other, the daily shedding is spread out and barely noticeable.
What changes in telogen effluvium?
A significant shock to the body pushes a large group of growing hairs into the resting phase at the same moment. Nothing seems to happen at first, because resting hairs stay in place for about three months. Then they all reach the end of their rest together and fall out over a few weeks. That is why the shedding appears two to three months after the trigger, when the cause has often been forgotten.
The important point is what does not happen: the follicle is not destroyed. Each shed hair is followed by a new growing hair from the same follicle, so the density returns once the cycle settles.
What causes telogen effluvium?
A review of the telogen effluvium literature lists drugs, physical trauma and emotional and physiological stress among the main triggers. In practice, the cause is usually something the body experienced as a significant shock two to three months before the shedding started.
Which illnesses and physical stresses can trigger it?
- High fever and infections, including flu and COVID-19.
- Surgery and general anaesthesia, or a serious accident.
- Childbirth: postpartum hair loss is the most familiar form of telogen effluvium.
- Rapid weight loss, crash diets and, increasingly, weight-loss injections such as Ozempic and Mounjaro.
- Severe emotional stress, such as bereavement, a divorce or a period of intense pressure at work.
Can COVID-19 cause telogen effluvium?
Yes, and it became one of the most common causes during the pandemic. A study of 204 patients in Istanbul found telogen effluvium linked to COVID-19 in about 28% of people within three months of infection. It started on average around 54 days after a positive test and was far more common in women (42%) than in men (6%), and more common in people who had respiratory symptoms. A systematic review of 465 patients found that most recovered, although a few had persistent shedding.
Which nutritional and medical causes should be checked?
- Low iron stores and other vitamin deficiencies linked to hair loss.
- Thyroid disease, both underactive and overactive.
- Starting or stopping certain medications, including some hormonal contraceptives, blood pressure and mood medications. Never stop a medication without talking to your doctor.
- Chronic illness such as kidney or liver disease, or autoimmune conditions.
How is telogen effluvium different from pattern baldness?
This is the question that matters most in a hair consultation. Telogen effluvium and androgenetic alopecia, better known as male pattern baldness or female pattern hair loss, can start in the same way, with more hair in the brush. But one recovers on its own and the other does not, and a comprehensive review of telogen effluvium points out that the two are often present together.
| Telogen effluvium | Pattern hair loss (androgenetic alopecia) | |
|---|---|---|
| Onset | Sudden, often two to three months after a trigger | Gradual, over years |
| Where | Whole scalp evenly, sometimes more noticeable at the temples | Hairline, temples and crown in men; top of the scalp and parting in women |
| Hair thickness | Shed hairs are normal, full thickness | Hairs become progressively finer (miniaturised) |
| Shedding | Heavy, noticeable on pillow and in the shower | Often little shedding; thinning is more visible than hair fall |
| Course | Recovers within 6–12 months once the trigger passes | Progresses without treatment |
| Hair transplant | Not a treatment | Can restore areas where follicles are lost |
How do doctors tell them apart?
- History: a clear trigger two to three months earlier strongly suggests telogen effluvium.
- Pull test: gently pulling a small group of hairs releases more resting hairs, with a white bulb at the root, when shedding is active.
- Trichoscopy: in pattern hair loss the hairs in the affected area vary widely in thickness; in pure telogen effluvium they do not, and short new hairs are often visible.
- Blood tests: ferritin, thyroid function and other tests look for a hidden ongoing cause.
What is chronic telogen effluvium?
In some people, mostly women between 30 and 60, shedding goes on for more than six months, often in waves. A study of 355 patients described this chronic form as starting abruptly, sometimes with no identifiable trigger, and running a long, fluctuating course. Unlike pattern hair loss, it rarely leads to visible bald areas, and the hair keeps its normal thickness. Anyone with shedding that lasts more than six months should be assessed, both to look for a continuing cause and to rule out pattern hair loss developing underneath.
How long does telogen effluvium last?
Acute telogen effluvium usually follows a predictable course:
- Months 0–3 after the trigger: no visible change while the affected hairs rest.
- Months 2–4: shedding starts, often suddenly.
- Months 3–6: shedding peaks and then slows as the trigger fades.
- Months 6–12: new hairs grow back; overall fullness returns gradually, at about a centimetre a month.
If the trigger continues, for example an untreated iron deficiency, an ongoing illness or repeated crash diets, the shedding continues too. That is the most common reason telogen effluvium seems to last for ever.
What are the signs of regrowth?
- Less hair on the pillow and in the shower than at the peak.
- Short, fine new hairs standing up along the hairline and parting.
- A pull test that releases only one or two hairs.
How is telogen effluvium treated?
The same literature review stresses that the essential step is to identify and remove the cause. In most cases that, and time, is all that is needed.
What can you do while it recovers?
- Find and treat the trigger: correct iron or vitamin deficiencies, treat thyroid problems, review medications with your doctor.
- Eat regular meals with enough protein, especially after illness or weight loss.
- Be gentle with your hair: avoid tight hairstyles, harsh chemical treatments and aggressive brushing while the hair is fragile.
- Manage stress and sleep, both of which can keep the shedding going.
Do medications or scalp treatments help?
Topical minoxidil is sometimes used to shorten the shedding phase and support regrowth, particularly in chronic telogen effluvium or when pattern hair loss is also present. It needs a doctor’s advice, and an initial increase in shedding is common when it is started.
In-clinic treatments such as PRP hair treatment and hair mesotherapy can support the scalp during recovery, especially when telogen effluvium and pattern hair loss occur together.
Is a hair transplant ever the answer?
Not for telogen effluvium itself. The follicles are still there and will grow back, so there is nothing to replace. During active shedding, a transplant would also be impossible to plan accurately: the scalp looks thinner than it really is, and the donor area at the back of the head can shed too.
A transplant becomes relevant only when, after the shedding has fully settled, some areas have clearly not recovered because pattern hair loss was also present. In that case the plan is made on a stable scalp, with an accurate picture of the donor area.
Dr. Erdoğan’s Perspective: Shedding Is Not the Same as Losing
Telogen effluvium is one of the most alarming forms of hair loss to live through and one of the most reassuring to diagnose. The hair falls out because the cycle has been disturbed, not because the follicles have been lost, and once the trigger is found and dealt with, the cycle resets.
The real task is to make sure that is the whole story. When shedding goes on for months, keeps returning, or leaves the hairline, crown or parting thinner than before, it is time to look for an ongoing cause or for pattern hair loss developing underneath, because those are the cases where early treatment makes a difference.
Still Shedding After Six Months? Find Out What Is Behind It
If your hair has not settled within six months, or some areas look thinner even after the shedding has stopped, an assessment can tell whether you are dealing with telogen effluvium, pattern hair loss or both. Send photos of your hairline, parting, crown and the back of your scalp, together with when the shedding began and any recent blood tests, and you will get an honest view of whether to wait, treat or plan restoration. If a transplant does become the right step once your scalp is stable, read how a hair transplant in Turkey is planned on a stable scalp, what a hair transplant in Turkey costs, and what the hair transplant package includes.
Frequently asked questions
How long does telogen effluvium last?
Acute telogen effluvium usually lasts three to six months, with full regrowth taking six to twelve months. If shedding continues for more than six months, it is called chronic telogen effluvium and should be assessed by a doctor.
Can stress cause hair loss?
Yes. Severe emotional stress is a well-known trigger of telogen effluvium. The shedding usually appears two to three months after the stressful event, which is why the link is often missed.
Does telogen effluvium cause baldness?
No. It thins the hair evenly across the scalp but does not cause permanent bald areas, because the follicles are not destroyed. Bald patches or a receding hairline point to another condition.
Is hair loss after COVID-19 permanent?
Usually not. Hair loss after COVID-19 is mostly telogen effluvium, starting around seven to eight weeks after infection, and most people recover fully. Persistent thinning should be checked for pattern hair loss or another cause.
Can telogen effluvium and pattern baldness happen together?
Yes, and it is common. Telogen effluvium can make existing pattern hair loss suddenly noticeable. When the shedding settles, the areas affected by pattern loss do not fully recover and need their own treatment.
This article is for information only and does not replace an in-person medical examination.
Sources
- Asghar F, et al. Telogen effluvium: a review of the literature. Cureus. 2020;12(5):e8320. doi:10.7759/cureus.8320
- Rebora A. Telogen effluvium: a comprehensive review. Clin Cosmet Investig Dermatol. 2019;12:583–590. doi:10.2147/CCID.S200471
- Aksoy H, et al. COVID-19 induced telogen effluvium. Dermatol Ther. 2021;34(6):e15175. doi:10.1111/dth.15175
- Hussain N, et al. A systematic review of acute telogen effluvium, a harrowing post-COVID-19 manifestation. J Med Virol. 2022;94(4):1391–1401. doi:10.1002/jmv.27534
- Whiting DA. Chronic telogen effluvium: increased scalp hair shedding in middle-aged women. J Am Acad Dermatol. 1996;35(6):899–906. doi:10.1016/s0190-9622(96)90113-9