The early signs that go unnoticed

It’s often a photo someone else took. A wedding, a birthday, you from behind or from above. And there, under the ceiling light, you can see your scalp in a place where you never used to. Since when? No idea. In your mirror, everything looked fine.

That’s what early hair loss is like: it moves quietly, and often in places you never look.

Why you don’t see it coming

The American Academy of Dermatology (AAD) puts it plainly: these signs can be subtle, so you may have hair loss for months or years before you notice it¹. Pattern hair loss (androgenetic alopecia, the hereditary kind) tends to progress very slowly, over several years or even decades².

Above all, hair doesn’t vanish overnight. In the affected areas, the follicle (the small pocket each hair grows from) shrinks over successive cycles. The hairs it produces become thinner and lighter, and shorter than the hairs around them, until they stop growing back altogether². Dermatologists call this miniaturisation.

An Italian team counted the hairs of 109 men, on the top of the head and at the back. In the early stages, the number of hairs on top hadn’t clearly dropped yet. Their conclusion: what makes early balding visible isn’t only that there are fewer hairs, it’s also that they get thinner⁵. You still have about as many hairs, but they cover less. That’s why the change is so hard to date.

In men: the temples, then the crown

The most common pattern starts with the front hairline receding, mainly in a triangle at the temples, followed later by thinning on the crown³. The French Society of Dermatology (SFD) describes the same order: the temples first, then the top of the head⁴. The sides and back of the head are spared².

Beware of false alarms. Almost all men of European descent see their temples recede a little in their teens³. So if you had a receding hairline at 18, it isn’t necessarily the start of balding. What matters is a recession that gets deeper every year¹.

French Society of Dermatology⁴

The crown has another problem: you almost never see it. A sparser patch that grows slowly can go years without a witness¹.

In women: the parting and the ponytail

In women, the front hairline is usually kept⁴. The thinning is concentrated in the middle and on top of the head, where hair gradually becomes finer and less dense³⁴. According to the AAD, the first noticeable sign is often a widening parting or a thinner ponytail¹.

The parting widens because scalp hair grows in small tufts. With pattern hair loss, each tuft loses hairs one by one, and scalp shows between them⁶. A common variant, called the “Christmas tree” pattern, also breaks into the front hairline at the end of the parting³.

It isn’t rare: the SFD puts it at about one woman in five by age 40⁴, and DermNet says around 40% of women show signs of hair loss by 50⁶. It often progresses in bursts, with faster phases of 3 to 6 months followed by stable spells of 6 to 18 months⁶. The possible causes are more varied in women: we go through them in the most common causes of hair loss in women.

Fine hairs in the basin

Sometimes there’s a clue at the bottom of the basin. Dermatologists in Beijing asked 176 adults to wash their hair every day over a filter cloth, three days running, and then measured every hair that fell⁷.

Among people with no hair problem, 93% lost no more than one very fine hair (a vellus hair) per wash. In people with pattern hair loss, there were 4.7 on average, and these fine hairs made up 8.3% of the hairs shed, against 1% in the others⁷. The authors draw a simple lesson: several tiny thin hairs in the plughole are worth a closer look⁷. The study is modest, with 71 people without hair loss and 77 with pattern hair loss, all Chinese and recruited from clinics.

Fineness matters more than numbers. A wash always takes some hairs with it, and losing hair every day is normal.

Why the mirror fools you

Even when we look, we judge ourselves poorly. An Australian study asked 103 men aged 30 to 70 to pick the drawing that looked most like them on the balding scale doctors use. Two trained observers did the same without telling them⁸.

Men under 50 got it wrong more often than older men⁸. The authors still consider this self-assessment good enough for surveys, and the sample is small. But the point stands: facing your mirror, you see neither your crown nor the slow change.

On forums, many people find out by chance, with no idea how long it’s been going on:

Posted on the HairLossTalk forum⁹¹⁰. Neither had a diagnosis yet.

When it’s a different picture

Everything above describes slow hair loss in a pattern. Hair loss that comes on suddenly, in handfuls or in patches, is a different picture, with other causes, such as major stress or childbirth. That kind should be shown to a doctor without waiting.

One sign alone isn’t a diagnosis either. A dermatologist looks at the pattern of the hair loss, the scalp and your family history². When in doubt, they examine the hair under magnification: differences in thickness of 20% or more between neighbouring hairs point towards pattern hair loss³. If you’re wondering when to talk to a doctor, it’s as soon as one of these signs is confirmed from one month to the next. Your doctor can then offer you a treatment.

Spotting the signs early, without relying on the mirror

Since these signs hide in slowness, the only way to see them is to compare your head with itself, months apart. A memory isn’t enough. A photo is.

Take the same set every week: same room, same light, same distance, hair dry and styled the same way. Aim at the areas in this article: both temples, the crown, the parting. They’re the ones you never see head-on. And start as early as you can: a first photo taken before the doubt sets in becomes your baseline.

Calvap is built for this. Your previous photo appears as a see-through overlay so you can line up in exactly the same spot, across 7 areas of the scalp, crown included. Your photos line up on a timeline, stay on your phone, and after a few months you can see whether your parting or temples are moving, instead of guessing.