What is the difference between telogen effluvium and pattern hair loss?

Part of: Hair & scalp

In telogen effluvium, the number of hairs shed increases diffusely and usually appears some time after the trigger, not the same day. The AAD says people normally lose about 50–100 hairs a day, and that noticeable shedding usually starts a few months after the triggering event; after childbirth, for example, noticeable shedding may begin around two months later. This differs from pattern hair loss, which shows as gradual thinning in a typical distribution, and the two can happen together.

Key numbers

  • 50–100 hairs/day — Normal shedding
  • A few months later — After a strong trigger
  • About 2 months — After childbirth — an example

What points to pattern hair loss?

Gradual thinning, a widening part in women or a typical receding/thinning pattern in men, and miniaturized hairs on trichoscopy point to pattern hair loss more than a story of sudden shedding alone. Having telogen effluvium does not rule out hereditary hair loss underneath it.

A direct comparison: telogen effluvium or pattern hair loss?

  • Onset: telogen effluvium comes on suddenly, months after a stressful event such as childbirth, an illness with fever, surgery, major weight loss or severe stress. Pattern hair loss is gradual, year after year.
  • Appearance: telogen effluvium means lots of hair on the comb, pillow and in the shower, with general thinning and no defined gaps. Pattern hair loss shows a widening part or a thinner ponytail in women, and a receding hairline or thinning crown in men.
  • Follicles: in telogen effluvium the follicles stay healthy and resume growing. In pattern hair loss they shrink gradually and produce finer, shorter hair.
  • Course: after telogen effluvium, hair usually regains its density within 6 to 9 months once the cause is gone. Pattern hair loss does not reverse on its own and responds better the earlier treatment starts.
  • They can coexist: telogen effluvium can unmask underlying pattern thinning, and then the hair does not return to how it was without assessment and treatment.
  • Sudden patchy bald spots, scale, or an itchy, burning scalp fit neither type and deserve an in-person examination.

Key takeaways

  • A trigger today does not usually cause heavy shedding tomorrow; telogen effluvium commonly has a delay.
  • 50–100 hairs a day is an approximate normal range, but the number alone is not a diagnostic test.
  • Trichoscopy and the pattern of thinning matter more than the amount of hair in the drain.

Hair Shedding or Pattern Hair Loss? How to Tell Which One You Have

Medical references

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