Evolving Concepts of Health: From Ancient Beliefs to Modern Understanding

For most of human history, being “healthy” meant very different things depending on where and when you lived. In ancient civilizations, a sudden illness might be blamed on an angry deity. In 18th-century Europe, a doctor might drain your blood to restore balance in your body. Today, we talk about mental wellness, social determinants, and environmental health as essential parts of the picture. The concept of health has not stayed static – it has evolved dramatically over centuries, shaped by cultural beliefs, scientific breakthroughs, and shifting philosophical frameworks. Understanding this evolution helps us appreciate why modern health science looks so different from its ancient counterparts.

Ancient beliefs about health: spirits, gods, and humors 🔗

Long before microscopes and laboratories, early human societies tried to make sense of illness and well-being through the lens of religion, spirituality, and philosophy. In many ancient cultures, disease was attributed to supernatural forces – the wrath of gods, possession by evil spirits, or punishment for moral failings. Ancient cave dwellers even drilled holes into the skulls of those they believed to be possessed, hoping to let evil spirits escape. In many early societies, healers were often priests or shamans who used rituals, prayers, and incantations as primary treatments.

The Church in medieval Europe, for instance, encouraged the belief that disease was divine punishment and relied on prayers to saints as a cure, which discouraged investigation into natural causes of illness. This supernatural view of health persisted across many civilizations for thousands of years and was only gradually displaced by more naturalistic explanations.

The humoral theory: balancing the body’s fluids 🔗

One of the most influential early frameworks for understanding health came from ancient Greece. The group of fourth- and third-century BC physicians known as the Hippocratics were the first organized group to consider that illness had natural, not supernatural, causes. This was a truly revolutionary shift in thinking.

At the core of their system was the humoral theory, which proposed that the human body contains four essential fluids – blood, phlegm, yellow bile, and black bile. Health was associated with a balance of these humors (eucrasia), while imbalance (dyscrasia) was thought to be the direct cause of all diseases. Each humor was linked to a natural element and a season. For example, phlegm was associated with water and winter, while blood was linked to air and spring.

This idea was not limited to Greece. Early texts on Indian Ayurveda presented a similar theory of three or four humors (doshas), which were sometimes linked with the five elements: earth, water, fire, air, and space. The parallels between Greek and Indian traditions suggest that the idea of bodily balance as the foundation of health emerged independently in multiple civilizations.

Hippocrates, often called the father of medicine, was central to formalizing this system. He synthesized existing philosophical opinions from a physician’s perspective, and his writings were preserved in a collection known as the Corpus Hippocraticum. His approach emphasized empirical observation – examining patients, studying symptoms, and considering environmental factors like diet, air quality, and climate.

Later, the Roman physician Galen (129-216 CE) expanded on Hippocratic ideas and became the dominant medical authority for over a millennium. Galen believed that an excess of any one humor caused illness, and treatment involved removing the surplus – for example, bloodletting to reduce excess blood or purgatives to expel bile. These practices, while ineffective by modern standards, dominated European and Islamic medicine well into the 17th century.

The germ theory revolution 🔗

The humoral framework began to crumble as scientific methods advanced. The real turning point came in the mid-to-late 19th century with the emergence of germ theory – the idea that specific microscopic organisms cause specific diseases.

Pasteur and Koch: founding figures 🔗

The germ theory emerged primarily through the pioneering work of French chemist Louis Pasteur and German physician Robert Koch. Pasteur’s experiments in the 1860s showed that microorganisms caused fermentation and spoilage, disproving the prevailing belief in spontaneous generation (the idea that life could arise from non-living matter). He extended this work to demonstrate that germs could also cause disease in living organisms.

Koch then conclusively established that a particular germ could cause a specific disease through his experiments with anthrax. He examined the blood of infected cows, identified rod-shaped bacteria, and successfully transmitted the disease to mice using those bacteria. This systematic approach led to what we now call Koch’s postulates – a set of four criteria for proving that a specific microorganism causes a specific disease. These criteria remain foundational in microbiology today.

Impact on medicine and public health 🔗

The acceptance of germ theory was transformative. At the end of the 19th century, nearly 30% of all deaths were due to infection; within a hundred years, the mortality rate from infectious diseases dropped to about 4%. This dramatic decline was driven by vaccines, antibiotics, antiseptic surgical techniques (pioneered by Joseph Lister), and improved public hygiene.

Germ theory encouraged the reduction of diseases to simple interactions between a microorganism and a host , which was both its strength and its limitation. It replaced the elaborate attention to environmental influences, diet, and climate that characterized earlier systems like humoralism. While incredibly effective for infectious diseases, this narrower focus would eventually need broadening.

The biomedical model: strengths and limitations 🔗

The success of germ theory gave rise to the biomedical model, which became the dominant framework for health in the 20th century. This model was developed during the age of Enlightenment and rests on the belief that science could diagnose and cure illness, making health something measurable by simply determining whether a disease is present or not.

Under this model, the body is treated essentially as a biological machine. When something breaks down, medical interventions – drugs, surgery, or other clinical procedures – are used to fix it. The biomedical model defines health simply as the absence of disease or disability, with emphasis on diagnosis, treatment, and curing diseases through medical interventions.

Where the biomedical model falls short 🔗

Despite its enormous contributions to modern medicine, the biomedical model has significant blind spots. It does not consider the emotional and social influences on health and prioritizes treating existing conditions rather than preventing them. A person may be free of any diagnosed disease yet still suffer from chronic stress, social isolation, poor nutrition, or environmental pollution – all of which significantly affect health outcomes.

Consider two individuals with the same medical condition – say, type 2 diabetes. One lives in a stable home with access to healthy food and supportive social networks. The other lives in poverty with limited healthcare access and high environmental pollution. The biomedical model would treat their diabetes similarly, but their actual health trajectories will be vastly different because of factors the model does not account for.

The ecological model: health in environmental context 🔗

As the limitations of the biomedical model became apparent, researchers developed ecological models of health that placed individuals within their broader environments. The ecological model views health as a product of complex interactions between individuals and their environments, considering individual, interpersonal, organisational, community, and societal factors.

This model draws on concepts from ecology itself. An ecosystem refers to the combined physical and biological components of an environment, with dynamic interactions among organisms and their nonliving surroundings – and any disruption in this ecosystem can have adverse impacts on health through complex pathways. Factors like land use, climate change, pollution, and loss of biodiversity all affect human health in ways the biomedical model alone cannot explain.

From individual to systems thinking 🔗

The ecological model introduced multiple levels of influence on health. At the individual level, genetics and personal behavior matter. At the interpersonal level, family and social networks play a role. At the community and societal levels, policies, cultural norms, and environmental conditions shape health outcomes. This model encourages integrated approaches and partnership between healthcare providers, communities, and policymakers.

The biopsycho-ecological model expands further by adding the physical environment as a fourth interacting element alongside the body, mind, and sociocultural variables. It recognizes that health outcomes emerge at the interface between a person and their total environment – an idea that resonates strongly with today’s environmental health science.

The modern holistic approach to health 🔗

The most significant redefinition of health in the modern era came in 1948, when the World Health Organization (WHO) wrote it into their constitution. The WHO defined health as “a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity.” This definition was groundbreaking because it explicitly moved beyond the biomedical view and embraced a multidimensional understanding of health.

Physical, mental, and social dimensions 🔗

The WHO definition links health explicitly with wellbeing and conceptualizes health as a human right requiring physical and social resources to achieve and maintain. It frames well-being as a positive aspiration, not just the absence of problems. This was consistent with what later became known as the biopsychosocial model, developed by psychiatrist George Engel in 1977, which considers physiological, psychological, and social factors together.

Mental health is an integral and essential component of health – indeed, there is no health without mental health. The WHO emphasizes that mental health is a state in which individuals realize their own abilities, cope with normal stresses of life, work productively, and contribute to their communities. This perspective has driven major policy shifts, including efforts toward parity between physical and mental health services.

From a static state to a dynamic resource 🔗

The WHO’s 1948 definition, while revolutionary, faced criticism for being too idealistic. In 1984, the WHO revisited and updated the definition, shifting it from a desirable state of being to a dynamic set of resources for living well – emphasizing social and personal resources alongside physical capabilities. The 1986 Ottawa Charter for Health Promotion further reinforced this view, describing health as a resource for everyday life, not the objective of living.

More recently, scholars have proposed even more refined definitions. One reconsidered 2020 definition describes health as “the dynamic balance of physical, mental, social, and existential well-being in adapting to conditions of life and the environment.” This recognizes health as fluid, continuous, and multidimensional – shaped by a person’s ability to adapt to changing life circumstances.

Holistic health in practice 🔗

The holistic approach to medicine emphasizes the integrity of each person’s physical, mental, and spiritual being, the psychosocial context of health and illness, and the importance of health promotion. It encourages a respectful partnership between physician and patient and draws from a variety of healing traditions.

Today’s holistic frameworks integrate what earlier models contributed. The biomedical model’s emphasis on scientific diagnosis remains essential. The ecological model’s attention to environmental and social determinants adds crucial context. And the biopsychosocial perspective ensures that mental and social well-being are treated as seriously as physical health.

In 1980, the environmental advocacy group Friends of the Earth expanded upon the WHO definition to include ecological well-being, stating that personal health involves planetary health. This idea – that human health cannot be separated from the health of ecosystems – has grown into what we now call the planetary health movement, which sits at the intersection of environmental science and public health.

Why understanding this evolution matters 🔗

Tracing the history of health concepts is more than an academic exercise. Each stage in this evolution addressed real gaps in understanding – from superstition to natural causes, from bodily fluids to microorganisms, from individual biology to social and environmental systems. Each transition built on what came before while correcting its limitations.

Today, the challenges we face – chronic diseases, mental health crises, environmental degradation, health inequities – cannot be addressed by any single model. The preventative approach brought by improvements in social health determinants needs to be balanced effectively with the remedial focus of the biomedical model and its advancements in diagnostics, technology, and vaccines. A truly modern understanding of health requires integrating all these perspectives.

The journey from ancient humors to holistic health also reminds us that our current understanding is not the final word. Definitions of health have always reflected the knowledge, values, and priorities of their time. As environmental challenges intensify and our understanding of the connections between human and planetary health deepens, the concept of health will continue to evolve.

What do you think? How much do you believe environmental and social factors shape your own health compared to genetics and medical care? And as our understanding of health keeps expanding, what dimension – mental, social, environmental – do you think deserves more attention in today’s healthcare systems?

References

1. https://pubmed.ncbi.nlm.nih.gov/11802300/
2. https://www.ncbi.nlm.nih.gov/books/NBK24649/
3. https://pmc.ncbi.nlm.nih.gov/articles/PMC7089083/
4. https://pmc.ncbi.nlm.nih.gov/articles/PMC3071421/
5. https://www.who.int/about/governance/constitution
6. https://www.who.int/data/gho/data/major-themes/health-and-well-being
7. https://www.sciencedirect.com/science/article/pii/S1936657421000753
8. https://www.healthknowledge.org.uk/public-health-textbook/medical-sociology-policy-economics/4a-concepts-health-illness/section2/activity3