Why Is My Hair Shedding? Normal vs. Excess Shedding

Why is my hair shedding every day?

Daily shedding is a normal part of how hair works. The American Academy of Dermatology (AAD) says it is normal to shed between 50 and 100 hairs a day.

The reason is that the hair cycle continually releases old hairs and replaces them. That routine shedding is not a sign of hair loss.

You may notice hairs on your pillow, in the shower drain or on your brush. Seeing some hair in these places is expected.

What counts as excessive hair shedding?

Excessive shedding means the body sheds significantly more hairs each day than usual. The AAD uses this definition, and the medical term is telogen effluvium (TEL-o-jen eh-FLOO-vee-um).

MedlinePlus describes how it can feel: hair tends to come out in handfuls when you shampoo, comb or run your hands through it.

StatPearls, a clinical reference, notes that collecting 100 or more hairs in 24 hours suggests telogen effluvium. That is a guide for clinicians, not a home test. Counting hairs is hard to do accurately, so a dermatologist is the best person to judge what is happening.

What happens in the hair cycle during excess shedding?

Excess shedding happens when stress on the body pushes many hairs out of the active stage and into the resting stage at once. Hairs in the active stage are called anagen, and resting hairs are called telogen.

StatPearls describes telogen effluvium as physiologic stress causing a large number of anagen hairs to abruptly enter the resting phase.

Cleveland Clinic says up to 70% of anagen hairs can prematurely enter the resting phase after a stressor or a change to the body. MedlinePlus gives a similar range, saying one half to three quarters of scalp hair may shed.

What are the common causes of hair shedding?

Common triggers include illness, surgery, childbirth, rapid weight loss, medications, hormonal changes and stress. StatPearls groups them as metabolic stress, hormonal changes or medications.

Specific examples from the sources include:

• A recent operation, major illness or sudden blood loss (AAD, MedlinePlus).
• A high fever or severe infection (AAD, MedlinePlus).
• Chemotherapy (AAD).
• Childbirth: a few months after giving birth, most women shed noticeable amounts of hair (AAD).
• Losing 20 pounds or more (AAD). Cleveland Clinic also says restrictive diets can lead to nutritional deficiencies that may contribute.
• Emotional or physical stress, which Cleveland Clinic calls one of the leading causes.
• Thyroid conditions: StatPearls says hypothyroidism, an underactive thyroid, can lead to chronic telogen effluvium.

Why did my hair start shedding months after a stressful event?

Shedding usually starts a few months after the trigger, not right away. The AAD says most people notice excessive shedding a few months after the stressful event.

A peer-reviewed review places it about 1 to 6 months after a triggering event. MedlinePlus likewise says you may not notice it for weeks to months.

The AAD gives a postpartum example: shedding appears about two months after birth and usually peaks around four months after. Because of this delay, it can be hard to connect the shedding to its cause.

Will shedding stop on its own?

Often it does. The AAD says that as the body readjusts, shedding stops, and within six to nine months the hair tends to regain its normal fullness. StatPearls calls acute telogen effluvium self-limited and spontaneously reversible.

Timeframes differ between sources. Cleveland Clinic says hair usually returns in three to six months. MedlinePlus says shedding decreases over 6 to 8 months, and that loss tied to menopause or childbirth often goes away after 6 months to 2 years.

There is a caveat. If the stressor stays with you, shedding can be long lived, and MedlinePlus notes it can become chronic. Because hair cycles vary from person to person, treat these figures as ranges.

When should I see a dermatologist about hair shedding?

See a board-certified dermatologist if shedding is heavy, sudden, patchy or continuing. A peer-reviewed review notes that increased shedding may signal an underlying medical problem and should be investigated appropriately.

The AAD says the sooner you find the cause, the better the outcome, and that the less hair you lose, the more successful treatment or prevention tends to be.

Shedding is not always telogen effluvium. Hereditary hair loss, tight hairstyles, harsh hair-care products, hair pulling and ringworm of the scalp are other causes the AAD names. A dermatologist can tell these apart. Please talk with a prescriber or dermatologist before changing any medication or supplement.