Telogen effluvium is a temporary, all-over shedding usually set off by a trigger such as illness or stress, while pattern hair loss is a slow, patterned thinning driven by genetics and hormones. They look and behave differently, and telling them apart changes what you should do.
What telogen effluvium is
Hair grows in cycles, and at any time a proportion of follicles are in the resting (telogen) phase before they shed. Telogen effluvium happens when a trigger pushes an unusually large number of follicles into the resting phase at once. A few months later they shed together, and you notice far more hair than usual coming out in the shower or on the pillow.
For scale, the NHS notes that losing 50 to 100 hairs a day is normal and usually nothing to worry about. In telogen effluvium the daily count can rise to several hundred, which is why the change feels so alarming. Most cases are acute and settle within about six months; shedding that continues beyond that is called chronic telogen effluvium and deserves a medical review.
Common triggers include a high fever or illness, major surgery, childbirth, significant psychological stress, rapid weight loss and some medicines. The shedding typically appears around three months after the trigger, which is why the cause is often overlooked. We explore the stress link in stress and hair loss, and rapid weight loss is covered in hair shedding and rapid weight loss.
What pattern loss is
Pattern hair loss (androgenetic alopecia) is different in almost every way. It is gradual rather than sudden, patterned rather than diffuse, and driven by inherited follicle sensitivity to DHT rather than a one-off trigger. It shows up as a receding hairline and thinning crown, described in what causes male pattern baldness.
Female pattern hair loss follows the same underlying process but looks different: diffuse thinning over the crown and a widening parting, with the front hairline usually preserved. Because that diffuse look can resemble telogen effluvium, women are more often caught between the two diagnoses. The key difference is the time course: female pattern loss develops slowly over years, while telogen effluvium arrives over weeks. Treatment differs too, with minoxidil for women being the usual first option for female pattern loss.
How to tell them apart
A few features usually separate them:
- Timing: telogen effluvium comes on suddenly, often months after a clear trigger; pattern loss creeps in over years.
- Distribution: telogen effluvium thins hair fairly evenly all over; pattern loss concentrates at the hairline and crown.
- Recovery: telogen effluvium usually recovers on its own; pattern loss continues without treatment.
- Amount: in telogen effluvium you see lots of shed hairs but rarely go bald; pattern loss can progress to visible baldness.
Sudden round bald patches are a different story again: they point to alopecia areata, an autoimmune condition that needs its own assessment and does not behave like either telogen effluvium or pattern loss.
Why the distinction changes treatment
This is the practical point. Telogen effluvium usually needs no drug treatment at all: once the trigger passes, the hair grows back over months, and the job is to identify and address the trigger, whether that is an iron deficiency, thyroid problem, crash diet or period of stress. Reaching for pattern-loss treatments would miss the point.
Pattern loss, by contrast, is progressive, so treatments that lower DHT or support growth are worth considering early. Mistaking one for the other wastes time and money, or leads to unnecessary worry. That is why getting the diagnosis right comes before any decision about treatment.
What helps telogen effluvium
Because telogen effluvium is a response to a trigger rather than a follicle disease, the most useful step is to find and address the cause. That might mean correcting an iron deficiency, treating a thyroid problem, easing off a crash diet, or simply allowing time after an illness or stressful period. Eating enough protein and overall calories supports recovery, and reassurance genuinely matters, because anxiety about the shedding can itself prolong it. Drug treatment is rarely needed and, importantly, would not fix a problem that is not being driven by DHT.
The British Association of Dermatologists' telogen effluvium leaflet is a good plain-English summary of the condition and its usual course. If you suspect a nutritional cause, our guide to which vitamin deficiencies cause hair loss covers what blood tests can check and what the evidence supports.
How to stop hair loss
It depends on which problem you have. Telogen effluvium generally stops itself once the trigger has passed; the aim is to support recovery rather than medicate the follicles. Pattern loss is the opposite: it will not stop on its own, but licensed treatments can slow it and often partially reverse it, and NICE guidance on androgenetic alopecia describes finasteride and minoxidil as the established options for men. Our guide to how to stop hair loss weighs the options in detail, and finasteride for hair loss can be prescribed privately after a clinical assessment. Whichever route you consider, confirm the diagnosis first.
When to seek advice
See a GP if shedding is sudden and heavy, lasts more than about six months, comes with other symptoms such as fatigue or changes in your periods, or if you simply cannot tell what is going on. Blood tests can pick up common contributors such as low iron, thyroid problems and vitamin D deficiency, and a clinician can distinguish the patterns in person. A photograph taken every month or two can also help you judge whether things are recovering, stable or progressing.
