Nine years ago, Israeli gynecologist Marek Glezerman was at the pinnacle of his career: He was the chief of three large departments and, with over two decades of experience under his belt, a prominent figure in his field. He felt good. Then he started reading Gender Difference, an obscure 1970s treatise on why men and women should be treated differently by physicians, and he started to rethink his work.

If tailoring care to different sexes strikes you as an obvious strategy, you’re probably not a doctor. The vast majority of medical care is supplied with no special attention given to gender differences. Glezerman now thinks that’s detrimental to not just the field, but to patients’ experiences. He also thinks it ignores some inconvenient truths about the future of both his field and the male sex.

“My research interest was turned into this fascinating area, which will change medicine profoundly,” he told Inverse. “And it is already changing medicine profoundly.”

Glezerman’s new book — Gender Medicine: The Groundbreaking New Science of Gender- and Sex-Based Diagnosis and Treatment(https://www.amazon.com/Gender-Medicine-Groundbreaking-Sex-Based-Diagnosis/dp/1468313185) — insists that not only are we on the cusp of a medical revolution, we might be on the verge of a biological apocalypse of men, who he calls the “weaker sex.” Inverse talked to Glezerman about his research and his predictions for the future of medicine.

Could you explain what gender medicine is?

Gender medicine is actually a rather self-evident issue. Gender specific medicine advances the issue that all body systems in men and women may look similar, but may work very differently. Half the human population of this world provides data, which are then extrapolated to the other half of the population. Until now, most research on drugs, and on diseases, has been performed predominantly in men. Most animal research is done on male subjects, even for female diseases. Since women and men are different in many different physiological terms, this seems very illogical. And the results being extrapolated to women, may — in the best of cases — not cause any big problems, but in the worst of cases, [they] may be dangerous, maybe even fatal.

Why is medical research so focused on men?

In this case, the explanation is as simple as “it’s more convenient and it’s cheaper.” Male research subjects don’t get menstruations and they don’t become pregnant; [among] humans, men don’t have to hurry home if a child is sick, or face hormonal fluctuations. So it’s easier and it’s cheaper. If you do research on men, then you can do an extrapolation on women, and if you believe that [that's okay], then that’s fine. But once you find out that there are differences, it’s no longer fine and something has to be done.

We could talk for hours now about medical situations where the knowledge about the differences between the sexes is so important. Take Ambien. It has been around for 20 years.

Women should only take half the amount. That means in women, Ambien stays longer in the system. So if she gets up in the morning and uses the suggested dosage — whose research has been done only on men — she has a 30 percent higher chance than men that she still has it in her system. And then she goes to the car and she drives — that’s bad.

But two years ago, the FDA, for the first time, published a directive to produce the drug with different dosages for men and women with regard to body weight. In the not too long future, we’ll be seeing medications for men and women on the shelves of pharmacies just like we see medications for children and adults.

I noticed that you didn’t really talk about transgender men and women. How does gender medicine potentially affect transgender men and women?

Once there is an intergendered issue at hand — transgender man goes the direction of female, or female goes in the direction of transgender man — then usually it’s in addition to the mental issues [patients have to deal with]. There is also a treatment issue. So if a man gets treatment by female hormones, or vice-versa — a female by male hormones — then [the medical] approach [is to aim for] the target sex, actually. There’s a lot to be researched here.

There were two specific chapters I found fascinating. One was when you argue that men are actually the weaker sex, and the other was the one about how men could possibly die out in the future. Could you expand?

Men are the stronger sex if you look at muscle mass and if you look at the fact that men are about 20 percent taller and larger in body strength.

But look at longevity. Women live longer than men. If you look at infectious diseases, men are much more prone to infectious diseases. Men have more problems if they’re operated upon. And along their life cycle, in each and every phase, men fare worse than women do.

Now this is an observation which is not new; we’ve known them for a long time. Look at just longevity. One [possible reason for this is that] women have developed a stronger immunological system, probably due to the fact that women are the ones to raise children, and if women are affected by diseases, we wouldn’t be talking now. So women have developed a strong immune system. On the other hand, a stronger immune system makes women also more vulnerable to autoimmune diseases. We know about 70, 80 autoimmune diseases, and most of them are in women. But if you take a look from the male side, the weaker immune system in males means they’re more prone to infectious diseases, which is a problem.

So concerning the genetics of that, you know our chromosomal makeup — we have 44 chromosomes which are in every inch and every cell of men and women — is identical. And we have two sex chromosomes. In a woman, we have XX, in a male we have XY. Now these chromosomes are in constant activity, and they’re also under constant attack because they need repair mechanisms, which are very sophisticated. Both chromosomes are exactly the same. They can repair themselves. They can help themselves out. They are pretty much identical.

In the sex chromosomes of women, you have XX. They can help each other out. But in the male you have XY, meaning that X can be repaired where other Xs appear, but the Y chromosome is a dead end.

And that is why in the population of mammals — which is about 300 million years old — both chromosomes X and Y have about a thousand genes in them or something like that. The X chromosome still has about 1000 genes, but the Y chromosome has less than 100. The vast part of the Y chromosome, which is also very small, is a genetic wasteland. Now if you calculate that, then in about 200 to 300 thousand years, there will be no Y chromosome.

Was the Y chromosome once just as strong as the X, and now we’re losing it? Is that what you’re saying?

I’m not talking about 1000 or 2000 years [in the past]; I’m talking about hundreds of thousands of years ago. The Y chromosome was richer in genes than it is today, if we think about it mathematically. If this continues, then there might be a time where these 80 chromosomes go down to 60, 20, then nothing.

In that kind of a world, how would we be reproducing?

First of all, let’s hope this world, as it is, will stay for now; it’s not very likely to last that long. But it could. On the other hand, it’s not the Y chromosome that’s the most important here, it’s a certain gene on the Y chromosome. And this certain gene is involved in a process which affects the primitive gonad, meaning that primitive gland develops either into a testicle or into an ovary. Now this specific gene could find a place on another chromosome. There are actually animals where this is already happening. We’ll be able to continue [as a species], but what the world would be looking like without a Y chromosome — that’s difficult to imagine.

We will probably not have procreation like we know it today. If you look at in vitro fertilization — it’s gotten more accepted and more successful. There might be other methods that develop because history is never linear. All kinds of things can happen.

This interview has been edited for clarity.

Tanya Basu is the Science editor at Inverse. Her writing focuses on the social sciences and behavior. Now based in Brooklyn, she will always call Chicago home and never be too full for one more taco.