Why Is My Hair Thinning?

The ponytail holder used to go around three times. Now it goes around four. And in last weekend’s photo, the part in your hair looked like a road.

What normal shedding looks like

The NHS¹ says we lose between 50 and 100 hairs a day, often without noticing. Cleveland Clinic² gives the same range.

So a few strands on the brush isn’t the problem. The question is if you’re losing more than that, or if the hair coming back is finer than it used to be.

Pattern one: the slow widening

The American Academy of Dermatology (AAD)³ describes it this way: your part often gets wider, and hair near your temples may recede. Women with this pattern don’t lose all their hair the way some men do. They get widespread thinning, and without treatment it can spread from a wider part to thinning across the whole head.

It runs in families. The AAD³ says you inherit the genes from your mother, your father, or both. Hormones play a part too, particularly after menopause. Cleveland Clinic² explains the menopause side: your hair follicles shrink, which makes your hair grow finer.

It’s also common. Cleveland Clinic² says more than half of women will notice hair loss, and female pattern hair loss affects about 30 million people in the United States.

Pattern two: the sudden shedding

This one feels like a different problem altogether, and it is.

Cleveland Clinic⁴ describes telogen effluvium as temporary hair loss caused by a stressor or a change in your body. The triggers include high fever, childbirth, severe infection, psychological stress, major surgery, thyroid disorders, stopping birth control, restrictive diets and certain medicines. The shedding shows up two to three months later, and you can lose up to 300 strands a day.

The delay is what confuses people. You’re blaming the shampoo you bought last week, and the culprit was the flu in July.

The good news is in the numbers. Cleveland Clinic⁴ says the acute form lasts fewer than six months and goes away in 95% of cases, and that hair typically grows back within three to six months without treatment. The chronic form lasts longer than six months and may have no identifiable cause.

Other things that thin hair

Cleveland Clinic’s² list of causes for women also includes thyroid problems, iron and vitamin deficiencies, certain medicines such as some blood pressure and gout drugs and high-dose vitamin A, rapid weight loss, and chemical hair treatments. The NHS¹ lists iron deficiency, illness, stress and weight loss among the temporary causes.

Several of those are things a blood test can check.

What a dermatologist does

The AAD⁵ says a visit starts with questions: how long you’ve had hair loss and whether it came on quickly. Then the dermatologist looks closely at your scalp, your nails and any other area with hair loss. A gentle pull test shows how your hair is growing and whether it breaks easily. If disease or a metabolic problem is suspected, you may need a blood test or a scalp biopsy, which can be done in the office. Cleveland Clinic² says the blood work can check vitamin and mineral levels and hormone levels such as thyroid.

The visit matters because other conditions can mimic female pattern hair loss, the AAD³ says. A diagnosis changes the plan.

Get that diagnosis before you pay a hair clinic. The NHS¹ says to see a GP first, so the cause gets identified.

What treatment can do

The AAD⁵ says there’s no single treatment that works for everyone, that the earlier you start the more likely you are to see regrowth, and that it can take months to see results. It also says that some hair loss, after childbirth, surgery or illness, can grow back on its own.

For pattern loss, the AAD³ calls minoxidil, a non-prescription 2% or 5% solution, the most-recommended treatment. Cleveland Clinic² says you have to follow the directions exactly and use it indefinitely. The NHS¹ puts it more bluntly: these treatments don’t work for everyone, and they only work for as long as they’re used. Minoxidil can irritate the scalp.

Prescription options exist, and a dermatologist can walk you through them. Cleveland Clinic² notes that some are unsafe during pregnancy or when planning one. The AAD⁵ describes laser devices and platelet-rich plasma as still under research.

The NHS¹ also says hair loss can be upsetting, and suggests counselling and support groups. Take that seriously. Losing hair is a loss.

The play

Try this: keep a photo log

Take a photo of your part in the same light on the same day each month.

Write down any fever, surgery, childbirth, new medicine, crash diet or hard stretch from the past six months, since telogen effluvium shows up two to three months after its trigger.

Bring both to the appointment.

When to get checked

Cleveland Clinic² says to see a dermatologist as soon as possible when you notice hair loss, because the sooner you start treatment the better it works. The AAD⁵ says treatment works best when started at the first sign. The NHS¹ says to see a doctor if you’re worried.

Book an appointment if any of these fit:

• Your part keeps widening, or your ponytail keeps shrinking
• Shedding has gone on for more than six months, which Cleveland Clinic⁴ uses as the line between acute and chronic
• You can’t name a trigger from the past six months
• You take a medicine on Cleveland Clinic’s⁴ list, or you’ve lost weight quickly
• You’re pregnant or planning to be, and you’re thinking about any treatment

Three loops or four, the first job is working out which pattern you have. That’s what the dermatologist does first, too.