Autumn Hair Shedding or Hair Loss? How to Tell the Difference

Every September the same thing happens in Seoul bathrooms: more hair in the drain, more on the pillow, and a brush that fills faster than it did in June. The question that follows is a fair one. Is this the season, or is this the start of hair loss?

If you already know your hair is thinning and want to understand the type and what treats it, our hair loss roadmap is the page to read. If the shedding began a few months after starting a GLP-1 medication, the GLP-1 hair loss guide covers that specific trigger. This page answers the narrower autumn question: what seasonal shedding looks like, how much of it is normal, and which signs mean it is something else.

Why hair sheds more in autumn

Each hair follicle runs its own cycle. A growth phase lasts years, a brief transition follows, and then the follicle rests for roughly three months before it releases the hair and starts a new one. The hair you find on the pillow today stopped growing months ago. What you see in September was decided in early summer.

The clearest measurement of that summer signal comes from Zurich. Dermatologists there took trichograms, plucked-hair counts that show what proportion of hairs are in the resting phase, from 823 otherwise healthy women who had come in complaining of hair loss, and followed the pattern across six years. The proportion of resting hairs peaked in summer, showed a second, smaller rise in spring, and was lowest in late winter (PMID 19407435). Add the three-month lag between a hair entering rest and leaving the scalp, and the release lands in early autumn.

Search data tells the same story from the other end. An analysis of twelve years of Google Trends data found hair-loss searches following a yearly cycle, highest in summer and autumn (PMID 29048738), and a 2025 letter repeated the exercise for the Southern Hemisphere, where the seasons run six months apart, and reported the pattern on that hemisphere's own calendar (PMID 40116230). DermatologyNews’ Seasonal hair shedding: why it peaks in autumn walks through the evidence in more detail.

One honest caveat: these studies describe a rhythm in the population. They do not say why it exists, and they cannot tell you whether your shedding this month is the rhythm or a distinct issue layered on top of it.

How much shedding is normal

The figure usually quoted is 50 to 100 hairs a day. During a seasonal shed the count runs higher for a few weeks, and hair that is washed every second or third day comes out in bigger batches on wash day, which makes the shower count look worse than the daily average.

The more useful distinction is between shedding and thinning. Shedding is hairs leaving; a seasonal shed is followed by regrowth, so the density you see in the mirror does not change. Thinning is density falling, and it shows up as a part line that looks wider than it did in last year's photos, or a crown or temples that the light gets through more easily. A shed with no thinning is the seasonal pattern. Thinning, with or without a dramatic shed, is not.

Timing is the other marker. Shedding that follows a specific trigger, such as an illness with fever, surgery, childbirth, a crash diet, or a new medication, starts about two to three months after the event and usually runs its course within six months. Dermatologists call this telogen effluvium. When it continues past six months it is classed as chronic and needs a proper work-up (PMID 31686886, PMID 33541773). A seasonal shed sits at the mild end of the same mechanism: a wave of follicles resting together, then releasing together.

Six signs it is not just the season

1. A widening part line, or a thinner crown or temples. This is the fingerprint of pattern hair loss, and it is by far the most common diagnosis a hair clinic makes. In one Swiss referral centre's ten-year series of more than 15,000 patients, pattern hair loss accounted for 67 percent of diagnoses; telogen effluvium, the shedding category, was 7 percent (PMID 40654548). An autumn shed often unmasks pattern loss that was already there, because thinner regrowth is more noticeable once the older hairs leave (PMID 31686886).
2. Shedding that has lasted more than three months, or a shed that gets heavier every autumn and recovers less each spring.
3. A trigger two to three months back. Fever, surgery, childbirth, rapid weight loss, a new prescription, or a change in hormonal contraception. Medication-induced shedding in particular is easy to miss because the drug and the hair loss are months apart (PMID 37591561).
4. Patchy bald spots rather than diffuse loss across the whole scalp. Patches point to alopecia areata or another distinct diagnosis and should be seen promptly.
5. Scalp symptoms. Itching, pain, scaling, or redness alongside the shedding suggests a scalp condition rather than a shedding cycle, and some of these scar the follicle if left.
6. Broken hairs of uneven length. Whole hairs with a small white bulb at the root are typical of a shed; breakage has a different cause.

None of these six can be settled with a home count or a pull at the temples in the mirror. Rebora, whose reviews shaped how dermatologists classify shedding, describes the most common mistake as the doctor minimising the complaint (PMID 31686886). The opposite mistake is starting a years-long treatment for a shed that would have stopped on its own by November. Both come from skipping the examination.

What a dermatologist actually checks

A hair loss consultation at our clinic starts with the timeline: when the shedding began, what happened in the two to three months before it, what medications have changed, and whether it has happened in previous autumns. The examination itself is a hair pull test, dermoscopy of the scalp to look at follicle openings and hair-shaft calibre, and a review of the pattern of any thinning. Where the history points to it, blood tests follow: ferritin, thyroid function, and a hormone panel are the usual set.

For patients who want to establish a plan in a single visit, the diagnosis, a prescription where indicated, and a first PRP session can be done on the same day. Sessions run 30 to 60 minutes.

What to do this autumn

• Count roughly, once. A rough tally on a wash day and a non-wash day is enough context for a consultation. Daily counting adds worry without adding information.
• Photograph the part line. Same light, same angle, top of the head, once a month. Density change is what the photographs catch and what a shed alone will not produce.
• Do not change everything at once. Switching shampoos, starting a supplement, and buying an over-the-counter hair product in the same fortnight muddies the picture a dermatologist later has to read.
• Set a date. If the shedding is still heavy at the start of December, roughly three months on, or if any of the six signs above appears sooner, book a consultation. International patients can send their travel dates; the hair-loss page explains what can be done in a single visit.

Frequently asked questions

Is it normal to lose more hair in autumn?

Yes, for many people. A six-year trichogram study of 823 women found the highest proportion of resting (telogen) hairs in summer, and a resting hair is released about three months later, which lands in early autumn. Shedding that is diffuse, settles on its own within a few months, and leaves your part line and density unchanged fits the seasonal pattern.

How many hairs a day is normal?

Around 50 to 100 hairs a day is generally quoted as normal shedding, and the count rises for a few weeks during a seasonal shed. The number matters less than the trend: a shed that keeps going past about three months, or that comes with visible thinning, is the point to have a dermatologist look.

When should I see a dermatologist about hair shedding?

Book if shedding lasts longer than about three months, if your part line is widening or the crown or temples look thinner, if there are patchy bald spots, or if the scalp itches, hurts, scales, or is red. Also book if the shedding began two to three months after an illness, surgery, childbirth, rapid weight loss, or a new medication.

What does a hair loss consultation involve?

A timeline of the shedding and its possible triggers, a scalp examination with a hair pull test and dermoscopy, a review of the hair pattern, and blood tests such as ferritin, thyroid, and a hormone panel when the history points to them. Treatment follows the diagnosis; a seasonal shed usually needs none.

Reviewed by

Written by Dr. SangYoul Yun, board-certified dermatologist and Medical Director of Delight Dermatology, Gangnam, Seoul. Evidence reviewed 2026-09-04.

Sources

1. Kunz M, Seifert B, Trüeb RM. Seasonality of hair shedding in healthy women complaining of hair loss. Dermatology. 2009;219(2):105-10. PMID 19407435 · DOI
2. Hsiang EY, Semenov YR, Aguh C, Kwatra SG. Seasonality of hair loss: a time series analysis of Google Trends data 2004-2016. Br J Dermatol. 2018;178(4):978-979. PMID 29048738 · DOI
3. McMullen E, Berkowitz J, Berkowitz M, Donovan J. Seasonal trends of hair loss in the Southern Hemisphere: an analysis of Google search patterns. Int J Dermatol. 2025;64(9):1718-1719. PMID 40116230 · DOI
4. Rebora A. Telogen effluvium: a comprehensive review. Clin Cosmet Investig Dermatol. 2019;12:583-590. PMID 31686886 · DOI
5. Chien Yin GO, Siong-See JL, Wang ECE. Telogen effluvium: a review of the science and current obstacles. J Dermatol Sci. 2021;101(3):156-163. PMID 33541773 · DOI
6. Alhanshali L, Buontempo MG, Lo Sicco KI, Shapiro J. Medication-induced hair loss: an update. J Am Acad Dermatol. 2023;89(2S):S20-S28. PMID 37591561 · DOI
7. Caballero Uribe N, Casañas-Quintana E, Trüeb RM. Frequency of types of alopecia in a single-centre hair referral clinic over a ten years period. Int J Trichology. 2025;17(1):20-24. PMID 40654548 · DOI

Medical disclaimer. This article is general education, not a diagnosis. Whether your shedding is seasonal or needs treatment is decided after an in-person scalp examination with a dermatologist.