How Telogen Effluvium Causes Hair Loss

Telogen effluvium is the second most common cause of hair loss, after androgenetic alopecia. To better understand telogen effluvium, consider some facts about hair:

At any given time, each hair on the scalp is in a different stage; some are growing, some are resting.

  • Typically, about 90% of hair is in the growth phase, called the anagen phase. A single hair can be in the growth phase for several years, growing half an inch each month.
  • The remaining 10% of hair is in a telogen phase called telogen. The telogen phase allows the follicles that nourish each hair to rest before producing new hair and starting the growth cycle again.
  • Hair falls out during the telogen phase.

Therefore, it is normal to lose about 100 hairs a day. However, in telogen effluvium, more hair than normal enters the telogen phase (telogen) and falls out. The word effluvium means “to flow out” in Latin, and this loss is often painful for those who experience it.


Different types of stress can cause more hair to enter telogen than normal, leading to hair loss in telogen effluvium.

Common causes of telogen effluvium include:

  • childbirth
  • High fever that causes illness (such as COVID-19)
  • Operation
  • severe emotional stress
  • Significant weight loss
  • an unbalanced diet
  • Certain medications (including beta-blockers, anticoagulants, and antidepressants)
  • stop birth control pills

Triggers for hair loss usually occur 3 months before hair loss is noticed, as it usually takes a long time for hair to go from anagen to telogen. In some cases, triggers were not recognized.

related symptoms

  • Thinning hair – this means the hair loss occurs on the entire scalp, not on a few bald spots
  • In more severe cases, hair loss may be noticed in other parts of the body, such as the underarms and pubic area
  • No other associated symptoms, such as itching, pain, or redness of the skin
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Your dermatologist or primary care physician can diagnose the condition based on your detailed medical history, description of symptoms, and an examination of your scalp and hair. He or she may gently tug at your hair to see how much hair is falling out and what stage of the hair cycle they are in.

Blood tests to measure levels of thyroid hormones, iron, vitamin B12, and folic acid may be needed to rule out these abnormalities as the cause of hair loss.

A skin biopsy of the scalp may also be helpful if another type of hair loss is suspected.

treatment solutions

Telogen effluvium does not require treatment as it will get better on its own. Hair follicles are not permanently damaged and new hair grows where it was lost.

This is especially true if it is due to short-term causes such as childbirth or an illness you have recovered from. If telogen effluvium is caused by ongoing physical stress, such as an overly restrictive diet or chronic emotional stress, the hair loss will not stop until the underlying cause is resolved.