The Story of Medicine

SHORT LIVES AND

THE LONG ART

IN SICKNESS AND IN HEALTH

The story of medicine is also the story of disease. It must give voice not only to the scientists and healers who have studied and combated disease and injury, but to the sufferers who have endured illness – and the proddings, pokings and experimentations of medical science.

It is tempting to think that the diseases and accidents that trouble humankind have always been there, always the same, and only our abilities to deal with them have changed. But it is not so.

Vital spark: when does life begin? And what creates human consciousness?

Epidemic diseases did not affect our distant forebears. An epidemic needs a reservoir – a population who will harbour the bacterium or virus and allow it to break out periodically in a flurry of new infections. When our ancestors roamed the plains and mountains and the land was sparsely populated, people were too spread out to provide such a reservoir. Contagious and epidemic disease is largely a product of urbanization, when people live in sufficient numbers and sufficiently close proximity to make person-to-person transmission an effective way for a disease to spread.

Nor are human diseases uniquely ours. We share more than sixty disease-inducing micro-organisms with dogs, fifty with cattle, and many with sheep, pigs and poultry.

When hunter-gatherers settled to farming around 12,000 years ago, close contact with animals increased our exposure to the bacteria, viruses and even parasites that preyed on them. Many diseases jumped the species barrier.

We have caught flu from pigs and fowl, colds from horses and measles from dogs or cows. It is not a one-way trade; research in 2008 suggests that tuberculosis in cattle originated in humans, not the other way round (as had been thought for years). It is not even a process that is finished. The emergence in the 1990s of variant Creutzfeld-Jacob disease in people who had eaten beef infected with BSE showed we are not yet off the hook, and the flu virus continues to cross the species barrier. The H1N1 variant which emerged in Mexico in 2009 originated in pigs.

The development of urban societies offered other opportunities for disease. War and trade carried disease to new places. The Romans probably brought bubonic plague to Europe from the east; Spanish conquistadors caught syphilis in their rape of pre-Columbian America, but exchanged it for smallpox, measles and flu which devastated local populations even more quickly than European swords and guns.

While a population that is accustomed to an illness becomes resistant to a degree, a new disease easily wreaks havoc. Eventually, as a society becomes habituated to it, a disease recedes in the general population and restricted to childhood, afflicting those who have not been exposed to it before.

What goes on in the world that is invisible to the naked eye is often crucial to our health – microscopes are a key medical tool

Cities are innately unhealthy. Until very recently, urban death rates were so high that cities could only be sustained by the constant influx of a new population from the countryside.

As well as a population reservoir that can harbour disease, cities have brought new illnesses of their own, arising from urban conditions such as polluted water supplies and overcrowding (cholera and typhoid), poor diet (scurvy), occupation-related disorders and diseases (emphysemia) and conditions brought about by pollution (bronchitis). Most recently, diseases of affluence have clustered in cities – the effects of substance abuse, over-eating and lack of exercise, for example.

THE FIRST DOCTORS

For as long as there have been sick or injured people, there must have been others trying to help them. For our most distant ancestors, systemic disease was a mystery, often approached with the aid of magic, superstition and religion. Injuries are less mysterious and more easily visible, and also more amenable to simple treatment. Splints and bandages were no doubt used for many thousands of years before we have any record of them. At some point, more than 5,000 years ago in some societies, a form of the medical profession emerged, with particular individuals who specialized in dealing with health problems. In some cases they may have used magical means; in others they used practical methods that were more or less efficacious.

The training of medics began at least 2,500 years ago in Europe, probably longer ago in the Far East. Since that time, we have come to understand much of how the human body works and how it goes wrong; what causes infections and what may cure them; the chemistry that governs life and can cause death. The history of medicine, medics and disease shows humankind coming to understand the bodies we inhabit, developing models for how we work and how diseases affect us. It encompasses the development of medicines, surgery and other interventions, and our attempts to control the innermost workings of the mind and of genetics. And, of course, it includes the histories of the people who have cared for the sick and struggled to extend the boundaries of knowledge.

Bring out your dead: a body is taken away for disposal during the Plague of London, 1665. Cities used to be so unhealthy that populations could only be sustained by a constant influx of new blood from the country

TO AND FRO

The story we will trace here begins in the ancient world. In China, India, Mesopotamia and Egypt, men (for it was mostly men) began to specialize in treating their sick colleagues. They tried to understand how bodies work and how they go wrong, and came up with different models and explanations.

The narratives of Chinese and Indian medicine pursued their own paths, and have diverted little in the last 2,000 years from their original directions. Western medicine has taken a circuitous route from its origins in Mesopotamia and Egypt. The story will take us from Egypt to Ancient Greece, where Hippocrates laid the foundations of modern medicine. From there we follow Hellenic doctors back to Egypt as they filled the hospital of Alexandria, and on to Rome where we meet Galen and Celsus. The rise of Arab culture picked up the legacy of the Greek and Hellenic doctors and fused it with what they learned from Indian, Egyptian and Byzantine medicine to make huge advances of their own. The wisdom of the Arab medics passed back to Europe through Spain and Italy, bringing too the works of the Greeks, lost to Europe for more than a thousand years.

From the Renaissance onwards, western Europe became the focus of advances in medicine. First Italy and then Germany, France and Britain produced medical schools and began a systematic scientific exploration of the human body and its ills. With the Enlightenment, the flourishing of science of all types contributed to medical advances. The new confidence in applying reason, challenging age-old authorities and breaking with traditional taboos and religious prohibitions led to rapid progress. Microscopes, chemistry, electricity, anaesthetics, antisepsis… developments came thick and fast that enabled medicine to advance by leaps and bounds. In just over a hundred years, from 1898 to the present, we have seen the advent of X-rays, microsurgery, transplants, IVF, lasers, robotic telesurgery, genetic engineering and the mapping of the human genome. We can work the magic our ancestors dreamed of, and explain exactly how it functions.

NOT OVER YET

Much has been achieved, but the story of medicine is far from finished. We are no closer than the Ancient Greeks to knowing at which point after conception life begins, or understanding what that magic spark is that animates flesh and blood and creates consciousness. We may be able to identify the cause of inherited deformity and disease, but we cannot yet fix genes to prevent its expression. There are diseases we cannot cure and injuries we do not know how to heal. We may wipe out one disease – smallpox – but a host of new ones appears, all just as deadly and incurable: AIDS, Ebola fever, SARS. There is much cause to celebrate the triumphs achieved by the men and women who have battled bravely, tirelessly – and sometimes foolishly – to conquer the ills that flesh is heir to. But there is no room for complacency: when the US Surgeon General said in 1969 that the book of infectious diseases was closed, he was speaking far too soon.

Anne Rooney

The workings of the body laid bare in one of Gunther von Hagen’s plastinated corpses

CHAPTER 1

‘WHAT A PIECE OF WORK IS A MAN’

The raw material of medicine is the human body and the work of medicine is to maintain the body in perfect condition – or restore it if it goes wrong. This entails knowing how the body should work when it is well. But humankind’s concept of the body and how it works has changed radically over time.

The current predominant western view is that the body is an incredibly complex set of finely tuned biochemical systems. But this way of thinking would be completely alien to an ancient Greek proponent of humoral theory. Even modern eastern practitioners are accustomed to thinking in terms of a body that channels energy, and would not recognize the western scientific model. Our present knowledge of the physical and chemical workings of the body has come about through a process of observation, experimentation and examination that has been particularly intense over the last 500 years. It is by no means complete. The path has been tortuous – not least for patients – but the journey of discovery has been a fascinating one.

On balance

It may seem obvious that it is not possible to gain much knowledge about the human body by looking just at the outside. Yet many societies around the world and throughout history have forbidden making any form of incision in a dead body.

Models of the body have been constructed from what could be observed and deduced from the exterior, from examining injuries and from intellectual models of the world in general. The earliest models of the body focused on balance – whether of energies, elements or ‘humours’. Strangely enough, our latest models of the healthy body also feature balance, though of a different type.

There are two broadly different ways of looking at the body and its state of health or illness. One is the holistic and often spiritually-oriented model that is characteristic of eastern philosophies; the other is the atomistic, physically-grounded model that underlies western medicine. This second model only developed once medical scientists were able to take the human body apart and examine its workings, as though they were dismantling an infinitely complex machine. It is a project that is still in progress.

Healing plants have been central to medicine for thousands of years

ENERGY IN THE BALANCE

Eastern medical systems are holistic. That is, they see the body and the spirit as one, governed by flowing and balanced energies. Therapies based around them have developed, evolved and receded, but the central premise that illness is caused by blockages in energy paths or the sluggish flow of energy has remained intact amongst proponents until modern times. This model of illness is very closely related to the spiritual status of the patient, because spiritual and mystical matters affect or dictate the flow of energy. The oldest surviving and continuing medical system is Ayurveda (the Sanskrit word for ‘science of life’), which dates from the Vedic age in India – around 3,500 years ago. In China, the oldest and greatest medical text, the Nei Ching (Canon of Internal Medicine), is still studied. It dates perhaps from the 3rd millennium BC, during the reign of Emperor Hwang Ti – and was possibly even written by him. Both Ayurveda and traditional Chinese medicine are still used by billions of people and the models of the body on which they depend are central to Buddhist and Hindu beliefs.

Chinese acupuncture aims to restore the flow of qi in the patient’s body

The medical knowledge at the heart of Ayurveda is said to have been revealed by divine beings. It is preserved in hymn-like verses and its supposedly divine source allows no space for improvement by medical science. Ayurveda teaches that a person should live for around one hundred years, in a state of physical, spiritual and mental wellbeing. This can be achieved by following a healthy lifestyle and responding quickly to signs of illness. The Ayurvedic practitioner treats the body, the mind and the spirit together, aiming to balance the three doshas – wind/spirit/air, bile and phlegm – in the body. The correct balance of these is fixed at the moment of conception and maintaining the balance, or returning to one’s correct personal balance, is the key to health. Ayurveda uses medicines derived from plants to stimulate the body to rebalance itself. It also makes use of yoga, meditation, massage and, when necessary, surgery.

QI

Traditional Chinese medicine also ties the physical condition of the body to the health of the spirit. The legendary emperor Shen Nung (approximately 2698BC) is credited with inventing medicine, working with the divine inspiration of the god Pan Ku: the creator, in Taoist tradition. Pan Ku is said to have overcome chaos and to have established the polar principles of yin and yang, which are mingled in all things. Yin is associated with cold, wet, shadow and the female aspect; yang is associated with heat, light, dryness and the male aspect. The two necessarily coexist, each defined by its opposite, and are held in balance in a healthy organism or system. In the traditional Chinese model, the body has 12 organs. There are six solid yin organs (such as the heart, the liver and the spleen) and six hollow yang organs (such as the small and large intestine, the bladder and the stomach). The organs correspond to 12 main meridian lines. In a healthy body, the yin and the yang organs are in balance, and yin and yang are in balance within individual organs or groups of organs. Any imbalance between the two, whether located in a specific organ or more generally, results in ill health: a ‘yang’ disease brings about an increase in the body’s yang factor and results in a ‘hot’ disease; a ‘yin’ disease causes too much yin in the body and a ‘cold’ disease follows.

Shen Nung, reputed inventor of medicine in Chinese tradition

Yin and yang together form a balanced whole

The balance and the flow of a special type of energy, called qi, is also considered instrumental in determining health or sickness. Qi flows easily through the healthy body along meridians, which are not physical conduits but intangible energy pathways. A blockage in the flow of qi causes illness; if the flow is seriously impeded, death is inevitable. To restore a healthy flow of qi and a balance of yin and yang, the Chinese doctor uses medicinal plants, massage, special diets, physical exercise regimes or acupuncture.

CHAKRAS

Buddhist and Hindu belief systems formed in India and Tibet teach that the body is governed by many chakras, or energy centres. There are seven major chakras: six are aligned in an ascending column from the base of the spine to the top of the head and one hovers outside the body, between the genitals and the knees. Each chakra is associated with different functions or aspects of consciousness. Chakras are invisible to the human eye, but believers maintain that trained energy workers can perceive them intuitively. They are said to look something like a funnel with petals.

The ideal situation is for the energy that emanates from the chakras low in the body to move upwards. Union with the divine is achieved through the perfect flow of energy from the top of the head. If there is an imbalance or an energy blockage in a chakra then physical or mental illness can result. There are many ways to get recalcitrant chakras back in order, including using special stones and chanting. Yoga, too, is said to open the chakras and encourage the flow of energy, helping to maintain health. In addition, each individual is said to have an aura, something like a border of energy around the body. It is considered important to keep the aura clean, because it can be polluted by foreign and negative energies and vibrations. Methods of cleaning the aura include dusting the space around the body with an owl feather, combing the space with the fingers, standing under a waterfall or – more banally – bathing in Epsom salts.

THE FOUR HUMOURS

From the 5th century BC until the 19th century, the predominant model of the body in Europe and the Middle East was of a vessel composed of four humours that had to be kept in balance if good health was to be maintained. The humours were black bile, yellow bile, blood and phlegm. Too much or too little of any one of these humours would lead to illness, which must be treated by restoring balance. The body was encouraged to produce more of the unbalanced humour, or expel the excess. The origins of humoral theory probably lie in Mesopotamia or Egypt, but the concept was developed in classical Greece. It survived for two millennia, associated largely with the great Greek doctor Hippocrates (see p.18). The humours were related to the four elements – fire, earth, air and water – from which, according to Pythagoras and Empedocles, everything on earth was created. These were combined with the elemental pairs of opposites identified by Alcmaeon: hot and cold, wet and dry, sweet and sour, and so on. Alcmaeon thought that health depended on the balance between these opposites. He used a political metaphor to define health and disease: if the opposing powers are balanced, the body is healthy, but if any one becomes king, disease results. Sources of imbalance included the environment, diet, climate and internal factors. Alcmaeon’s model did not require any recourse to the supernatural or the mystical, but suggested that the patient could be healed without the intervention of the divine, simply by restoring the disturbed balance.

In traditional Indian medicine, six chakras (energy centres) are located at major branchings of the nervous system

Humoral theory was concerned with mental health and temperament as well as with physical wellbeing. This aspect of humorism was first developed by the Graeco-Roman doctor Galen (AD129–c.216), one of the most influential figures in the history of medicine (see p.22), and later by the 11th-century Arab doctor Avicenna. Like Hippocrates, Galen believed that health required a balance of the four humours, but he went further by asserting that there could be an imbalance of humours in an individual organ which could lead to a local disorder. After Hippocrates and Galen, diseases were categorized and treated according to the particular humoral imbalance that was thought to produce them. Different temperaments and proportions of humours were believed to be natural at different stages of life; old people would incline towards a cold, dry condition, while young people would be hot and moist. This helped to explain why some diseases were common at certain stages of a person’s life. An old person might be prone to arthritis, rheumatism and other cold, moist conditions, for instance. The nature and cure of a disease depended on its humoral qualities – so leprosy, a cold disease, must be treated with heat.

ALCMAEON

Alcmaeon, a contemporary of Pythagoras, was associated with the medical school at Croton in the 5th century BC. He was one of the pioneers of Greek rational medicine, which set the foundation for the whole of western medicine. Alcmaeon recognized the brain as the seat of the intellect and the senses and suggested that it was connected to the sensory organs by channels (poroi). He discovered the Eustachian tube in the ear, he distinguished arteries from veins, he possibly found the optic nerve and he described a model of