No one bald in the family, so why me?

Your dad is 60 with a full head of hair. So is your uncle. At family dinners, people even tell you you’ve got “good genes”. And yet, at 25, your temples are receding or your crown is thinning. So where does it come from?

There are two possibilities, sometimes mixed together: inheritance that’s quieter than you’d think, or hair loss that has nothing to do with inheritance.

Inheritance that doesn’t always show

Common pattern hair loss, which doctors call androgenetic alopecia, is largely inherited. It can come from your mother’s side as well as your father’s¹. The French Society of Dermatology (SFD) adds a detail that changes everything: hair loss is often found in other family members, but not necessarily in the generation just before you¹.

A family “with no one bald” often hides pattern hair loss that nobody noticed, for several reasons:

• First, age: according to the SFD, about 15% of men are affected at 20, 30% at 30, and one in two at 50¹.
• Then, pace: pattern hair loss progresses slowly, over years or even decades². A grandfather who lost his hair around 60 isn’t remembered as a bald man.
• Finally, women: in them, pattern hair loss thins the top of the head but usually keeps the front hairline³, and it doesn’t make them bald the way it can in men⁴. An affected mother or grandmother easily goes unnoticed. Yet male relatives of affected women are more often bald, a sign of partly shared genes³.

How it’s passed down, from the X chromosome to the famous maternal grandfather, is explained in our article pattern hair loss: from your mother or your father?. Here, we look at the case where the family seems to have been spared.

Hundreds of genes, a unique mix

Pattern hair loss doesn’t depend on a single gene that you either have or don’t. The British Association of Dermatologists (BAD) counts over 190 genes involved, from either or both parents, which explains why it affects members of the same family to very different degrees and at very different ages².

The largest study on the subject goes further. Researchers analysed the DNA of 205,327 men of European descent, aged 40 to 73, who had picked from four pictures the one closest to their own hair loss. They found 624 regions of the genome linked to pattern hair loss⁵. Each one weighs little. It’s the total that counts.

In practice, two parents with little hair loss can each carry some of these variants. Their child gets half of each parent’s genes, picked at random. The child can inherit a heavier mix than either parent, just as easily as a lighter one. That’s what makes hair loss seem to “come out of nowhere”.

Genes aren’t everything either. In this study, about 62% of the differences in hair loss between men were put down to genes, and the authors say this figure may be overestimated, because relatives also share an environment⁵. One limit to bear in mind: hair loss was reported by the participants themselves, and only men of European descent were included⁵.

Your dad isn’t the best guide

The same study calculated the weight of genes in two ways: by comparing brothers, then fathers and their sons. The result speaks for itself.

The researchers offer a partial explanation: a father and son don’t share an X chromosome, which a son always gets from his mother⁵. And that chromosome matters in pattern hair loss. So a dad with a full head of hair says little about what you inherited from your mother’s side.

The European guideline does note a strong paternal influence on the risk, in both directions. But it describes pattern hair loss as polygenic: it isn’t a trait that passes straight from father to son³.

“No one in my family is bald”

On a hair loss forum, young men describe exactly this situation⁶.

Posted on the HairLossTalk forum⁶.

The first had mentioned that grandfather in his own post, while describing a family with almost no hair loss. It’s a common reflex: you think of your dad, rarely of the rest of the family tree.

Other causes to rule out

Hair loss with no family history may also have nothing to do with genes. The most common kind of temporary shedding, telogen effluvium, doesn’t run in families and has no genetic cause⁷. It usually starts around three months after a trigger: childbirth, an illness with a high fever, surgery, extreme dieting, stress or a major life event, a new medicine, or stopping a hormone treatment such as the pill⁷. In one in three people, no cause is found⁷.

It doesn’t look quite like pattern hair loss: hair falls from all over the scalp, with a loss of volume rather than receding temples or a bald crown⁷. And it usually settles on its own: the shedding phase lasts 3 to 6 months, then new hair starts to grow⁷.

Other causes to look for:

• low iron, a thyroid problem, or a lack of vitamin D or B12, which a blood test can pick up⁸;
• a medicine: never stop a treatment without talking to the doctor who prescribed it⁹;
• in women, a hormonal imbalance such as polycystic ovary syndrome⁹: we cover the causes of hair loss in women elsewhere;
• alopecia areata, where the immune system attacks the hair follicles⁹, or hairstyles that keep pulling on the roots⁹.

What settles it

The family tree is only one clue among others. For the SFD, pattern hair loss is diagnosed mainly by examination: the doctor looks at where the hair is thinning and at the scalp and hair¹. With a dermatoscope, a lit magnifier, they look for hairs of different thicknesses, typical of pattern hair loss¹. No blood test is routinely needed when the picture is typical¹. The European guideline adds a pull test and a look at the eyebrows, body hair and nails, to rule out telogen effluvium, alopecia areata or scarring alopecia³.

One detail often reassures younger men: almost all men of European descent see their hairline recede a little at the temples during their teens³. So a receding hairline at 18 doesn’t always mean pattern hair loss.

If you’re unsure, your GP or a dermatologist can tell the difference. And if it is pattern hair loss, your doctor can suggest a treatment. The BAD notes that hair loss starting early can progress faster²: all the more reason to know early.

Track it instead of guessing

With no example in the family, you have nothing to go on for what comes next. The only way to know whether your hair loss is progressing, slowing down or stopping is to watch it over time. And the mirror isn’t much use: light, angle, wet hair or a different style change everything from one day to the next.

Pattern hair loss progresses over months and years. Telogen effluvium settles within a few months. With Calvap, you take a comparable photo every week: your previous photo shows through as a transparent overlay so you can line up in the same spot, and your photos sit on a dated timeline. Aim at your temples, crown and part. After a few months, you’ll see which of the two stories is yours. And if you see a doctor, you bring dated photos. Your photos stay on your phone.