Telogen effluvium: causes, how long it lasts and treatment

BAD says there is normally no treatment required for telogen effluvium because the hair will naturally start to grow back, and that taking medication does not speed up the process of regrowth. The aim is to find and, where possible, deal with any trigger, such as iron deficiency, and to be patient.

BAD lists self-care measures: avoid harsh brushing or combing, limit heated hair tools, avoid bleaching or relaxing treatments or anything using harsh chemicals, limit tight hairstyles, consider stopping smoking because cigarette smoke can worsen hair loss, and eat a balanced diet including iron, protein, fresh fruit and vegetables. It suggests considering supplements if your diet is restricted, for example vegan or vegetarian.

If the scalp becomes visible, BAD describes camouflaging hair fibre powder or spray and volumising shampoo as ways to disguise thinning. It says it is very unusual for telogen effluvium to cause thinning severe enough to need a wig, but wigs are available on the NHS with a consultant prescription, which may need a financial contribution from you.

Most people become aware when the amount of hair they are losing increases, most noticeably after washing or brushing, or as more hair in the shower drain, on a hairbrush or comb, or on the pillow. BAD says the onset is typically sudden and without warning.

Hair shedding usually occurs from all over the scalp, and you may notice a decrease in hair thickness and loss of volume rather than patches. Usually there are no other symptoms, but occasionally there is tenderness and altered sensation in the scalp, known as trichodynia.

BAD says telogen effluvium usually gets completely better without any treatment. The shedding phase of the hair cycle lasts between 3 and 6 months, after which new hair starts to grow, and it may take many months for hair to return to normal volume and thickness.

It is considered chronic if it lasts for more than 6 months. BAD also warns that it can recur if an underlying cause such as iron deficiency is not treated. If hair shedding does not get better, it recommends seeing your doctor to rule out other causes of hair loss.

BAD notes that telogen effluvium can occur at the same time as male or female pattern hair loss and sometimes leads to an early diagnosis of it, which is another reason to get persistent thinning assessed.

BAD says increased shedding occurs because of a disturbance of the normal hair cycle. Normally only about 15% of scalp hair is in the shedding (telogen) phase, but in telogen effluvium this rises to 30% or more. The disturbance is to the hair cycle rather than damage to the follicle, which is why hair usually regrows.

Right Decisions Scotland notes in its alopecia pathway that excessive shedding occurs three to four months after pregnancy or another major event, and that any new medications should be considered.

BAD says that telogen effluvium affects all age groups and both sexes equally, and that it does not run in families or have a genetic cause.

Scalp hair grows in cycles. BAD explains that around 85% of follicles are in the growth phase (anagen) and around 15% are in the resting phase (telogen). When a follicle enters telogen it stops growing, rests for two to four months, then a new hair begins to grow and pushes the old hair out. Losing 30 to 150 hairs a day is therefore normal.

In telogen effluvium there is a large increase in the number of hairs in the shedding phase, and because hair is lost at the end of the resting phase, the shedding often becomes obvious around 3 months after the trigger. That delay is why many people cannot link their hair loss to an event that now seems long past.

BAD says diagnosis is usually made by looking at the scalp and taking a medical history. A hair pull test, in which hair is gently pulled to see whether more than usual comes out, may be done, though it can be falsely negative if the hair has been washed within 48 hours. Hairs may be plucked and examined under a microscope, and very rarely a skin biopsy is needed when the diagnosis is uncertain.

A blood test may be carried out to exclude other causes such as thyroid conditions and iron deficiency. Right Decisions Scotland suggests checking a full blood count, ferritin and thyroid function for diffuse alopecia.

Childbirth is one of the triggers BAD lists. Right Decisions Scotland says excessive shedding occurs three to four months after pregnancy or another major event, and advises reassuring patients that telogen effluvium will recover spontaneously.

The general information above applies: the shedding phase lasts 3 to 6 months and hair usually regrows without treatment. If shedding is still heavy beyond 6 months, BAD recommends seeing a doctor to rule out other causes, and iron deficiency is among the causes a blood test can check for.

BAD recommends seeing a doctor if the hair shedding does not get better. Right Decisions Scotland lists referral to dermatology for diagnostic uncertainty, persistent or extensive alopecia and inflammatory scarring alopecia, and says patients with a severe degree of alopecia caused by disease can be considered for an NHS wig prescription.

Patchy hair loss is a different pattern. Right Decisions Scotland describes alopecia areata as patchy hair loss, and scarring alopecia as loss of hair follicles with or without inflammation and accompanied by scarring, which needs secondary care referral. These are reasons not to put patchy or scarring loss down to telogen effluvium.

Hair loss can be upsetting. BAD says some people find it helpful to join a patient support group, and signposts Alopecia UK, which offers information that can help people with other types of hair loss too.

On the NHS, assessment usually starts with your GP, who can arrange blood tests and, where needed, refer to dermatology. Right Decisions Scotland suggests checking full blood count, ferritin and thyroid function for diffuse hair loss.

Private dermatology is another route. Whichever you use, ask what tests are proposed and why, and be cautious about products that promise to speed up regrowth, since BAD says medication does not speed up regrowth in telogen effluvium.