Count or photograph?

On Monday you counted 63 hairs in the shower drain. On Wednesday, 112. On Thursday you didn’t wash your hair and found about twenty in your brush. So is it getting worse or not?

Those numbers can’t tell you. Not because you’re counting badly, but because a count of shed hairs doesn’t measure what you actually want to know: are you keeping your volume?

What a hair count tells you

Dermatologists sometimes use daily hair counts: you collect the hairs shed in a day, count them and bag them, for seven days¹. The threshold everyone quotes, 100 hairs a day, is arbitrary. Two Indian trichologists point this out in a review of hair evaluation methods: no clinical study or standardised method has ever validated it¹.

The other figures don’t agree any better. In a study of 404 women, average hair loss ranged from 28 to 35 hairs a day¹. British dermatologists give a range of 30 to 150 for most people². And the same Indian authors came across estimates of normal ranging from 10 to 250¹.

Your own count moves too, without your hair loss changing. Resting hairs come out mostly when you wash and brush². On wash day you find more; the day after, fewer. If you wash your hair every three days, your count follows that rhythm. Our article on how many hairs you lose a day goes through what makes the number vary.

A count can even reassure you wrongly. The review’s authors note that fewer than 50 hairs a day can be abnormal in someone who has already lost half their hair volume¹: with fewer hairs left, fewer fall out.

What falls out isn’t what’s missing

Most of the time, a hair that falls out is pushed out by the new one growing from the same follicle. The total number of hairs stays the same². The hair growth cycle means you lose hairs every day without losing any hair overall.

The American Academy of Dermatology separates two things. Shedding is a temporary surplus of hairs falling out. Hair loss is when something stops the hair from growing³. A count sees the first. It can’t see the second.

In pattern hair loss, this is even clearer. Hairs in the affected areas first become thinner and shorter than those in unaffected areas, before they disappear⁴. A thin hair that falls counts as one, just like a thick one. Your count can stay steady while your parting widens.

What people who count say

On a hair loss forum, the topic comes up again and again. Those who count mostly describe what it does to their mood⁵.

Testimonials posted on the HairLossTalk forum⁵⁶.

The same member adds that the only way to tell whether things are getting better or worse is to see what your hair looked like a couple of months ago⁶. That’s exactly what dermatologists say.

The tests dermatologists use

In clinic, a doctor has two simple tests to check whether shedding is active. They are for diagnosis, on a given day. They aren’t designed to track you at home week after week.

The first is the pull test. The doctor takes a tuft of about 20 to 60 hairs between three fingers and tugs firmly but not forcefully¹. The classic threshold: the test is positive if more than 10% of the hairs in the tuft come out¹. A team in Ottawa ran the test once, on the crown, in 181 volunteers: on average 0.44 hairs came out per pull, and 97.2% lost 2 or fewer⁷. The authors therefore suggest treating 2 hairs or fewer as normal⁷.

When people had last washed their hair made no difference to their results⁷. But participants washed and brushed as they liked: the team recorded it but couldn’t control it⁷. The British leaflet, for its part, warns that a test done within 48 hours of washing may be falsely negative². The test remains imprecise: the force varies from one doctor to another, the number of hairs grasped is hard to estimate, and a negative test rules nothing out¹.

The second is the wash test. You don’t wash your hair for 5 days, then wash it over a basin with the plughole covered by gauze. The hairs collected are counted and sorted by length, 3 cm or less on one side, 5 cm or more on the other¹. This sorting helps tell temporary shedding apart from female pattern hair loss, where short, fine hairs are far more common¹. Here too, no cut-off has been established¹.

Tracking over time: photos

To judge change over months, the European guideline on androgenetic alopecia ranked the available methods. Standardised global photos came first, because they look at the whole scalp in the same way, without relying on the patient’s or the doctor’s impression⁸. Its authors advise using them in routine practice too, for long-term follow-up⁸. The French Society of Dermatology calls them an excellent tool for tracking change over time⁹.

The Indian review puts it simply: comparing with an earlier photo beats remembering what your hair was like 3, 6 or 12 months ago¹. It also asks for the same hairstyle and colour from one photo to the next¹.

These photos only work if they’re taken the same way. A team in Ohio cites a study in which 22.66% of the hair had to be lost on standardised photos before 75% of dermatologists spotted the change¹⁰. If the light or the angle changes, a real difference goes unnoticed, or a false one appears. The rules for getting it right at home are in our guide to comparable photos.

How often to compare

Hair changes slowly. Male pattern hair loss usually progresses over several years, sometimes decades⁴. Temporary shedding lasts 3 to 6 months, and it’s called chronic beyond 6 months².

From one week to the next, then, you’ll see almost nothing. A weekly photo does something else: it gives you regular points, taken in the same conditions, so you can compare today’s photo with the one from three or six months ago. Compare area by area, too. The hairline, the temples and the crown don’t move at the same pace, and the back of the head, rarely affected, works as a reference.

If your photos show a parting that widens or an area that thins over the months, it’s a good time to talk to a doctor. You show them dated images rather than a list of numbers.

Comparing yourself with Calvap

Calvap replaces counting with comparing. At each session, your last photo of the area appears see-through over the camera view. You move until the two line up, then take the shot: same angle, same distance, week after week.

Your photos line up area by area on a timeline, with your routine alongside. Drag the slider between your first photo and today’s and you see what has changed over months, where a count would only have given you tonight’s number. The photos stay on your phone.