The Health Gap: Why do we still know less about women's health?
Imagine you go to the doctor with some symptoms.
The doctor looks up his textbook.
The symptoms don't quite match. They look similar – but not exactly what's in the book.
You will still be prescribed medication.
It has been tested.
It is approved.
It works.
Just not necessarily on a body like yours.
Because for decades, medicine was primarily tested on men.
Women were either excluded from studies or considered biological deviations from the standard.
Researchers today call the result the health gap – a systematic gap in our knowledge about women's health.
The article is written by Cathrine Widunok Wichmand
What is the “health gap”?
Before we dive into the historical context that enables the gender gap in health research, let me explain the health gap:
The health gap represents the difference in knowledge, diagnosis and treatment between men's and women's health, based on decades of underrepresentation of women.
Women are diagnosed later than men for several diseases
Women experience side effects from medication more often
Women-specific diseases are still underfunded in research
Women have a lower chance of surviving fatal illnesses such as a heart attack.
The health gap or gender gap in health has been going on for decades and is still costly for both women and society as a whole.
A historical view of the female body
However, we need to go back further than 1977 to understand what precedes such a decision being made. It reveals how deeply ideas about gender have been embedded, including in medicine.
We can already see back in antiquity that the female body was often described as a form of biological deviation from the male. The Greek physician Galen described women as a kind of “incomplete men” , where the difference consisted primarily in the reproductive organs.
For centuries, hysteria was one of the most common diagnoses in medicine, already described on papyrus scrolls in Egypt, and also mentioned by, for example, Hippocrates and Plato.
The "diagnosis" was a widespread theory that the uterus could wander around the body, and where it 'got stuck' it could cause disease. The word hysteria comes from the Greek word hystera , which means uterus.
In periods, hysteria was treated with drastic interventions – including surgical removal of reproductive organs or long-term institutional treatment.
And the theory and violent treatment to cure hysteria influenced medical research for centuries, right up to the 1900s, as a way to sicken and control women.
But religion has also played a role in the view of the woman's body. How was Eve created? From a rib from Adam. Also in the Book of Leviticus, menstruation is described as impurity.
But it's not just in Christianity that menstruation has been considered impure, you find the same thoughts in Islam, among others. And this view of a naturally occurring biological function in the female body has contributed to the tabooization of the female body.
It is also justified to mention the education systems. For centuries, education was reserved for men - it was not until 1875 that Denmark had its first female student in higher education. Knowledge is also power, so when you prevent half the population from getting an education, who is to say the learned against it?
But we don't have to go all the way back to our great-grandparents to see the same structures repeated. In the period 1920-1950, several researchers believed that menstrual blood contained so-called "menotoxins" - toxins that could affect and kill plants, food, or animals. Today, of course, we know that menstrual blood does not contain toxins.
Therefore, the historical context is important.
It shows how structures and systems have influenced medicine.
And how they have combined to ensure that knowledge about the female body is still limited.
The Reference Man: When the Male Body Became the Standard in Medicine
Once the history is in place, we can delve deeper into medical research. Well into the 20th century, the male body was considered the standard model in medical research.
One would consider the male body as the standard, the reference.
The female body was a deviation from the standard, an anomaly.
This view was also systematically integrated into research worldwide with the concept of 'the reference male'. The reference male would be described verbatim in countless medical books from the mid-20th century and decades onwards - even books that have been used until recently.
But the model had a serious weakness.
Nature is more complex than one standard body: a white male in his 20s, 5'7" tall, and 150 lbs. To state the obvious: The average patient is not a 150 lbs. male in his 20s.
This approach to medical research meant, among other things, that:
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medicine was developed and tested primarily on men
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symptoms of illness were described based on what was seen in male patients
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diagnostic criteria were developed based on male data
The basic idea was that the average patient is a man. We know that's a lie, but that was the starting point. They couldn't - or didn't want to - accept that the results of the research and experiments could be significantly different if they included a female body. The female body has a different biology than the male body.
This affects the results. But it was considered too cumbersome - also because it was too expensive.
However, the reference man not only influences medicine – also design and safety in everyday life.
For decades, car safety systems were tested with crash test dummies based on the male body.
This means that women, on average, have about a 73% higher risk of being seriously injured in car accidents because safety systems like airbags and seat belts are designed based on male body measurements.
Not only were women excluded by the use of the reference man. So were older people, children, and people of a different ethnicity than the white man.
And that's how knowledge gaps arise.
How women were excluded from medical research
Once the male body had been made the standard in research, the next step was to exclude women completely from many studies.
One was that it might have made research more difficult. But it was also believed that for safety reasons it was necessary to explicitly exclude women.
This movement gained momentum when the 1960s saw several drug scandals – especially after trials with thalidomide , which was given to pregnant women to reduce morning sickness but ended up causing serious birth defects in thousands of children.
This shocked the world, and in response, the US Food and Drug Administration (FDA) introduced guidelines in 1977 that recommended excluding women of childbearing age from early clinical trials . However, the guidelines were so broad that many research communities in practice completely failed to include women in studies.
The result of that decision was that millions of women were effectively excluded from early medical research for more than a decade. This ban was only lifted in 1993 in the US, and in the EU, this thinking was only seriously addressed in the 2000s.
The consequence was a huge data gap in the understanding of women's diseases, medical treatments, and side effects.
When did people start taking women's health seriously?
With The NIH Revitalization Act of 1993 made it mandatory to include women in federally funded clinical trials. Since then, representation has improved - although today we still do not see the same 1:1 ratio between women and men in clinical trials.
Many researchers still believe that we are only at the beginning of understanding the biological differences between the sexes that can affect diagnosis and treatment. It is not insignificant that both men and women be included in research. A review in The Lancet suggests that gender differences can affect:
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Disease incidence
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Symptoms
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Disease course
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Response to treatment.
Yet many studies still do not analyze results broken down by gender.
How does “the health gap” manifest itself today?
Today, the consequences of decades of research bias can still be seen in our modern healthcare system. We see this, for example, in late diagnoses.
A Danish study that analyzed data from the entire population showed that women are, on average, diagnosed later than men for a number of diseases - including diabetes, cancer and neurological disorders.
A classic example is heart attack.
For many years, symptoms of heart attack were described in terms of male patients: pressing pain in the chest that radiates into the left arm.
Women often experience other symptoms – for example, nausea, extreme fatigue, shortness of breath, or pain in the back and jaw.
When symptoms do not fit the textbook "classic" picture, diagnosis can be overlooked or delayed - in the case of a heart attack, it can cost lives.
The research also indicated that symptoms in women often:
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interpreted differently
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considered “atypical”
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or attributed to psychological factors.
We also see this with medication - both in terms of effect, dosage and side effects. Women often react differently to medication than men.
The explanation lies, among other things, in biological differences.
Women have a hormonal cycle, a different fat distribution and a different enzyme activity in the liver.
All factors that can affect how drugs are broken down in the body.
A well-known example is the sleeping pill zolpidem, which is found in the medication Ambien, among other things.
In 2013, the US FDA had to halve the recommended dose for women after research showed that women break down the drug more slowly than men – and therefore had a greater risk of side effects such as drowsiness and traffic accidents the next day.
You also see this with psychiatric diagnoses such as ADHD, where women are largely diagnosed late, often only when burnout has occurred in adulthood.
The most common biological process we know the least about
A third area where knowledge gaps are seen is in research into women-specific diseases. Several diseases that primarily affect women have historically been under-prioritized in research.
Examples include:
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endometriosis
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menopause
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autoimmune diseases
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menstrual disorders
This means that many patients still experience long diagnostic processes. Endometriosis is a good example: On average, it takes about seven years from the time a patient first sees a doctor until the diagnosis is made.
The most common biological process is the one we know the least about: menstruation.
For example, until a few years ago, there was no standard definition of “normal menstrual pain” in medical research.
The health gap is not just an abstract research problem.
This is evident in everything from medication doses to traffic safety – and ultimately in human health.
The economic and social cost of the health gap
The health gap does not only affect the quality of life of individuals.
It affects the entire society.
According to analyses from McKinsey and the World Economic Forum, women globally live 25% more of their life years in poorer health than men .
The researchers also estimate that closing the gender gap in health could create up to $1 trillion in economic value each year globally . But new figures from the Danish Chamber of Commerce, 2026 also show that if the health gap between women and men is closed, it could contribute to an annual boost of 1% of GDP, equivalent to approximately DKK 30 billion in Denmark alone.
If the knowledge gap between men and women were closed, it could lead to:
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fewer years of illness
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higher work participation
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lower healthcare costs
So to get everyone on board:
It's not just an equality issue.
It is also a socio-economic investment.
Towards new horizons for women's health
Fortunately, decades of flawed decisions are slowly being corrected. In recent years, significant progress has been made. Several fields of research now focus specifically on women's health, including:
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reproductive medicine
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hormone research
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menopause
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cycle-based medicine
At the same time, new technological areas such as femtech have emerged, where digital solutions are developed to understand and improve women's health. This is also pushing traditional areas.
There has also been a greater focus on gender-disaggregated data in medical research. Unfortunately, several researchers continue to point out that there is a lack of:
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financing
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larger datasets about women
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more gender-specific medicine.
Just take the Danish doctor Amani Meaidi, who our interview with tells us that she still has to conduct most of her research into hormonal contraception on a voluntary basis = without pay (which would normally be covered by research funding from both the public and private sectors).
The future: From “one-size-fits-all” to precision medicine
For many years, medicine has been based on the same standard: a white man of 170 cm. Regardless of whether the patient was in fact a black woman of 160 cm.
Fortunately, today, research is moving towards precision medicine. Treatment tailored to the individual patient. In that model, gender is an important biological factor.
This may mean that future research will focus more on:
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gender differences in disease
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hormonal influences
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individual treatment strategies
We will move from medicine for men, which should work for everyone, to making medicine for everyone that works for everyone.
The health gap has not arisen because the female body is more mysterious or more difficult to understand than the male body.
It arose because medical research for decades has been based on one type of body – and treated it as the standard.
It is a reality that billions of people live with.
When symptoms are misunderstood.
When medicine works differently.
When diseases are detected too late.
The consequences of this knowledge gap still affect diagnoses, treatments, and research today.
But something is changing.
More researchers are now turning their attention to the biological differences between genders, and new technologies make it possible to collect data we previously did not have access to.
This means that the medicine of the future will hopefully no longer be based on one standard body.
But in humans.
Sources
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Nature Communications – diagnostic delays study
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The Lancet – sex differences in medicine
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NIH Office of Research on Women's Health
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World Economic Forum & McKinsey Health Institute
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Caroline Criado Perez – Invisible Women
