You run your fingers through your hair and come away with a small bundle. The shower drain clogs every few days, the pillow is covered in strands and you start counting hairs on the bathroom floor. In many cases this kind of sudden, all-over shedding has a name, telogen effluvium, and the good news is that it usually stops on its own once the cause is found.
How much shedding is normal
Everyone loses hair every day. The American Academy of Dermatology puts normal shedding at about 50 to 100 hairs a day. People with long hair notice it more, and you will see more hair on days you wash or brush after a break.
Each hair follicle runs through a cycle. The growth phase (anagen) lasts two to seven years, followed by a short transition of a few weeks (catagen) and a resting phase of around three months (telogen). At any moment roughly 85 to 90 percent of scalp hairs are growing and the rest are resting. Resting hairs eventually fall out and a new hair starts in the same follicle.
What happens in telogen effluvium
A shock to the body pushes a large number of growing hairs into the resting phase at the same time. Nothing visible happens at first. About two to three months later those hairs are released together, and the shedding seems to come from nowhere. That delay is the reason people rarely connect the hair loss with what caused it.
The hair thins evenly over the whole scalp rather than in a bald patch. The parting may look wider and a ponytail thinner, but the scalp itself looks healthy, without redness or scars. Many hairs that fall out have a small white bulb at the root, which is typical of a resting hair.
Common triggers
- High fever or a serious infection, including COVID-19 and flu
- Childbirth (postpartum shedding usually peaks around three to four months after delivery)
- Surgery, an accident or a stay in hospital
- Crash diets, quick weight loss or too little protein
- Iron deficiency and low ferritin
- Thyroid problems, both underactive and overactive
- Stopping or changing hormonal birth control
- Some medicines, for example certain blood pressure drugs, retinoids or anticoagulants
- Severe emotional stress, such as a bereavement, divorce or job loss
Look back about three months from when the shedding started. Very often something on this list happened then.
How a doctor confirms it
A GP or dermatologist will ask about the last few months, look at the scalp and often do a gentle pull test, pulling on a small group of hairs to see how many come out. Blood tests are common: a full blood count, ferritin (iron stores), thyroid hormones (TSH) and sometimes vitamin D or zinc.
The doctor will also check that it is not something else. Pattern hair loss thins mainly the crown or the parting, alopecia areata causes round smooth patches, and scalp conditions show redness or scaling. These sometimes overlap with telogen effluvium, which is why a proper look is worth it.
Treatment and how long it takes
For most people the treatment is to fix or wait out the trigger. After a fever or childbirth there is nothing to fix and the shedding slows down within a few months. If the cause is low iron, a thyroid disorder or a medicine, treating that problem lets the hair cycle return to normal.
- Shedding usually eases within three to six months after the trigger is gone.
- New short hairs appear along the hairline and parting first. They are a good sign.
- Getting back to the previous thickness can take six to twelve months or longer, especially with long hair.
- Eat enough protein and iron-rich food, and do not start high-dose supplements without a blood test. Too much vitamin A or selenium can itself cause hair loss.
- Some dermatologists suggest minoxidil to speed up regrowth, although it is not needed in every case.
When shedding lasts longer than six months it is called chronic telogen effluvium. It is more common in women aged 30 to 60, tends to come and go, and is worth reviewing with a dermatologist.
What helps while you wait
Telogen effluvium does not make you bald. Even heavy shedding rarely removes more than half of the hair. Gentle care helps the hair you have look fuller: a wide-tooth comb, a mild shampoo, less heat styling and loose hairstyles instead of tight ponytails. A shorter layered cut can hide the thinning while the new hair grows in.
Stress about the shedding does not usually restart it, so try not to count hairs every day. Taking a photo of your parting once a month gives a much more reliable picture of the recovery.
Sources
- American Academy of Dermatology, Do you have hair loss or hair shedding? aad.org
- Hughes E. C., Saleh D. Telogen Effluvium. StatPearls, NCBI Bookshelf. ncbi.nlm.nih.gov
- NHS, Hair loss. nhs.uk
