Why Is My Hair Falling Out? The Causes That Can't Wait

Hair falling out usually comes down to hereditary thinning that creeps in over years, or a burst of shedding months after illness, childbirth or stress. Neither is an emergency, but both are worth getting checked, and hereditary thinning responds better the earlier it's treated. The scarring kinds can't wait, because a scarred follicle can't grow hair again.

If the drain is catching more hair than it used to, or your part looks wider than in last summer's photos, you're in large company. Cleveland Clinic says studies show more than 50% of females will experience noticeable hair loss. Where your hair is thinning also tells you how quickly to get it looked at.

How Much Hair Loss Is Normal?

Losing 50 to 100 hairs a day is normal, according to the American Academy of Dermatology (AAD). If you're losing more than that, telling shedding from true hair loss goes through the signs one by one.

Why Is My Hair Falling Out All of a Sudden?

Sudden shedding all over your head usually started with something that happened months ago. The AAD says most people notice the excess shedding a few months after the stressful event. That delay makes the cause easy to miss.

The AAD's list of triggers includes losing 20 pounds or more, giving birth, a high fever, surgery and stopping birth control pills. Caring for a sick relative, a divorce or losing a job can do it too. Once the trigger passes, hair tends to regain its normal fullness within six to nine months.

Medication is the trigger people forget. Mayo Clinic names drugs for cancer, arthritis, depression, heart problems, gout and high blood pressure among those that can cause hair loss. If the shedding started after a new prescription, ask the prescriber about it rather than stopping the drug yourself.

The month-by-month version is in how stress shedding starts and stops, and there's a separate guide to shedding after pregnancy.

Hair Loss Causes in Women, Sorted by How Long You Can Wait

Where the hair is going, and how fast, sorts most causes into three groups.

Less urgent, but still worth a doctor's visit:

• Even shedding all over, starting a few months after one of the triggers above. This is stress shedding, and it tends to settle on its own. Mayo Clinic still advises seeing a doctor if you're losing more than usual when combing or washing, partly to rule out other causes.
• A part that widens slowly, or overall thinning on top. The AAD says this is usually the first sign of hereditary hair loss in women, the most common cause of hair loss worldwide. There's no emergency, but treatment for female pattern hair loss works better started early.

Worth a doctor's visit soon:

• Hair that comes out in clumps when you brush. The AAD says some people with thyroid disease notice this, and a thyroid problem behind hair loss shows up on a blood test.
• A round or oval bald patch. That's often alopecia areata, which the AAD says can't be cured, though treatment can help hair regrow.
• Scaly, sometimes inflamed patches on the scalp, which the AAD links to scalp infection. Once the infection clears, it says hair tends to grow.

See a dermatologist now:

• Hair loss or a small round balding patch at the center of the crown, sometimes with small bumps, burning, stinging or itching.
• A hairline receding along the front and sides, or eyebrows that have thinned for no clear reason.
• Broken hairs, soreness or a receding edge where your style pulls tight.

That last group is easy to dismiss, because none of it looks dramatic at first. All three can become permanent.

Which Types of Hair Loss Are Permanent?

Hair loss that scars the follicle can be permanent. Scar tissue replaces the follicle, and the AAD says once a hair follicle scars, it can no longer grow hair. CCCA and FFA are scarring kinds. Traction alopecia isn't described by the AAD as scarring, but it can become permanent the longer it goes untreated.

Central centrifugal cicatricial alopecia (CCCA) starts at the crown. The AAD calls it a type of alopecia that can cause permanent hair loss and says it's more common in Black women. It often begins as a small, round patch in the center of the scalp that grows over time. Some people feel small bumps, and many with untreated CCCA report burning, stinging or itching.

Early treatment is the difference. The AAD says treating CCCA early may let you regrow some hair, and can stop it spreading outward.

Frontal fibrosing alopecia (FFA) starts at the front. The AAD says it's usually diagnosed in women after menopause, though it can start earlier. It often looks like a hairline receding along the front and sides of the head.

The first sign you may see is often eyebrow loss. Mayo Clinic says early treatment of a receding hairline (frontal fibrosing alopecia) might help avoid significant permanent baldness.

Traction alopecia comes from styles that pull. The AAD says it can be permanent the longer it goes untreated. Its warning signs include pain from tightly pulled hair, scalp stinging, crusts and broken hairs around the forehead.

The styles it names include cornrows, locs and braids worn too tight, tightly pulled buns, ponytails and up-dos, and weaves or extensions, especially on relaxed hair. Thinning edges and whether they grow back covers what to change first, including how to wear braids.

Is My Relaxer Causing My Hair Loss?

A relaxer can damage hair, but crown thinning isn't automatically the relaxer's fault. The AAD says coloring, perming or relaxing can damage hair and, over time, lead to hair loss.

Whether relaxers cause the scarring kind at the crown isn't settled. One 2011 study recruited 529 African American women at workshops in the central and southeast US. It rated central hair loss from photographs and a questionnaire.

Extensive central hair loss had no obvious association with relaxer or hot comb use. It was associated with a history of scalp ringworm (tinea capitis). There were no scalp biopsies, so the study couldn't confirm which cases were CCCA. The authors said hair care practices need more detailed study.

Dermatologist Oma N. Agbai, writing for the AAD, says there are many misconceptions that Black women are causing their hair loss through their styling.

The common causes it lists for Black women include CCCA and traction, but also female pattern hair loss, alopecia areata and stress shedding. So if your crown is thinning, switching products and waiting isn't a plan. A diagnosis is.

Could It Be Iron, Thyroid or Hormones?

Sometimes, and a blood test is how you find out. The AAD says not getting enough biotin, iron, protein or zinc can cause noticeable hair loss. Taking large amounts of vitamin A or selenium can cause it too, so more isn't safer.

Hormones count. The AAD lists polycystic ovary syndrome (PCOS) as a common cause of the hormone imbalance that can thin hair. Cleveland Clinic says the shifting hormone levels of menopause can make hair grow thinner. Whether your hair loss is hormonal or nutritional walks through the clues, and iron deficiency hair loss covers the iron tests to ask about.

If you take biotin, tell your doctor before any blood test. The NIH says biotin above recommended amounts may cause false results in some lab tests, including thyroid hormone tests. It also says biotin deficiency is very rare in the US.

What Will a Dermatologist Check?

Expect questions first. The AAD says a dermatologist will ask how long you've had hair loss and whether it came on quickly. Then they'll look closely at your scalp and nails. Gently pulling on your hair shows whether it breaks easily.

If a deficiency, hormone problem or infection is suspected, you may get a blood test or a scalp biopsy, done in the office. Cleveland Clinic says the blood tests check levels such as vitamin D, B vitamins, zinc, iron and thyroid hormone.

Before you go, note when the shedding started and what happened in the three or four months before it. List every medicine and supplement, biotin included. A photo of your part every few weeks, in the same light, shows slow change better than words.

Should I Be Concerned If My Hair Is Falling Out?

Be concerned enough to see a doctor if your hair loss is sudden or patchy, or you lose more than usual when combing or washing. Mayo Clinic says sudden hair loss can signal a medical condition that needs treatment.

Cleveland Clinic advises seeing a dermatologist as soon as possible whenever you notice hair loss. Don't wait at all for a small balding patch at the crown, a receding hairline, eyebrow loss, or pain where your style pulls. Weeks matter for the scarring kinds.

Frequently Asked Questions

Can Hair Loss in Women Be Reversed?

Often, yes, depending on the cause. After stress shedding, hair tends to regain its fullness within six to nine months of the trigger passing. For hereditary thinning, the AAD says minoxidil usually takes about 6 to 12 months to show results. Scarring hair loss can't regrow once the follicle scars, but early treatment can stop it spreading.

Why Is My Hair Falling Out in Clumps?

Clumps when you brush can come from a thyroid problem, according to the AAD, and round bare patches can mean alopecia areata. Heavy stress shedding can feel like clumps too. Any of these is worth a doctor's visit.

Why Is My Hair Thinning on Top?

Overall thinning or a widening part is usually the first sign of hereditary hair loss in women. Thinning that starts in the center of the crown, especially with small bumps, burning, stinging or itching, can be CCCA. That one needs a dermatologist early, because it can scar.