Misconceptions about Medieval Medicine: Humors, Leeches, Charms, and Prayers
By Michael Livingston
17 March 2003
Lef man laeces behoth.
[A weak man needs a physician.]
--Cotton Maxims I.45
When I attempted, some months ago, to provide a basic guideline to medieval maps for the readers of Strange Horizons, the project quickly evolved into an exercise in myth-breaking, and the result was the article "Modern Medieval Map Myths: The Flat World, Ancient Sea-Kings, and Dragons." This evolution, though surprising to me at the time, was a natural one: preconceived notions of the Middle Ages are strongly entrenched in our culture, and they must be dismantled before more reliable notions can be developed. This need to unlearn is particularly necessary for our Western culture, since we seem to feel that we already "know" the Middle Ages. We've seen Braveheart, after all; we've been to Cinderella's castle in Disneyland. We've read about King Arthur and Robin Hood. What more could there be?
Well, quite obviously, there's a lot more. (Otherwise, I would be out of a job). And to find the truth requires that we abandon our preconceptions, our suppositions that we already know what the Middle Ages are like. It's hard, but it is necessary. And it's the reason I do what I do for a living. In approaching the topic of medieval medicine, therefore, I have opted to follow the same path: a general introduction to medical practices in the Middle Ages accompanied by a bit of myth-breaking.
Approaching the Middle Ages
There are two primary fallacies that must be avoided when attempting to study a culture that is unfamiliar, and they are especially dangerous when we are examining a culture from the past. The first is to see the other culture as unsophisticated when set alongside our own. It is easy to do this, especially when we are looking at medicinal practices. It's very easy for us, as residents of the twenty-first century with advanced technologies and an unheard-of quality of life, to look back on the medical practices of the Middle Ages with a mixed measure of revulsion and awe. Our stomachs turn at an image of leeches growing fat on the warm blood of the sick; our minds are horrified by the fact that medieval doctors honestly believed the best remedy for a patient might be to open a vein and drain off quarts of precious blood; our hearts ache to think of virulent diseases ravaging bodies while a physician recited incantations or a priest prayed for deliverance of the patient from pain. In the same vein, we are often equally filled with amazement and awe that, despite such revolting medical practices, the human race survived at all to produce such humane and urbane, all-knowing and all-controlling creatures as ourselves.
This is foolishness. Medieval people were not stupid; they were acting in accordance with the finest knowledge about the human body that they had at hand. To even qualify such action as ignorance is to tread on thin ice indeed since it presupposes our own superiority in such matters. Yes, our modern doctors know more (or at least think they know more) about the causes and cures of diseases than their medieval counterparts, but we cannot think less of medievals for doing what they did. After all, their studies and experiences led directly to the discoveries that shape modern medicine.
The second fallacy to be aware of is positivistic thinking. As Bryon Grigsby describes it, this sort of thinking leads us "to see medieval medicine as a precursor or primitive form of twentieth-century medicine. In order to do this effectively, critics construct a narrative by which the discoveries of the future are foreseen in the documentation of the past." While it is true that discoveries, in a genealogical sense, build upon one another (one thinks of Bernard of Chartres' metaphor -- made famous by Isaac Newton -- about standing on the shoulders of giants), it does not follow that we should mine the past for those moments when medieval practitioners "got lucky," so to speak, and did something "right." What we need to understand, what we must understand, is that medieval medicine was a vibrant, complex, learned system that makes complete sense when viewed on its own terms. Given the facts that doctors had to go on, they did remarkably well in creating hypotheses to fit those facts and in constructing systems of theory to fit those hypotheses. I think that if a modern physician were pressed on the point, he or she might concede that little has changed in this regard: practices are continually revised or refined as new information comes to light. Even at the beginning of this new millennium, we "know" very little.
With these pitfalls in mind, let us turn to what the realities of life in the Middle Ages were, what information doctors had to go on, and what systems they developed to accommodate the facts at hand. Since I like to think that I know something about it, let's get an idea of what it was like to live in, for example, turn-of-the-millennium England.
The Good Life
This is how the present life of man on earth . . . appears to me in comparison with that time which is unknown to us. You are sitting feasting with your ealdormen and thegns in winter time; the fire is burning on the hearth in the middle of the hall and all inside is warm, while outside the wintry storms of rain and snow are raging; and a sparrow flies swiftly through the hall. It enters in at one door and quickly flies out through the other. For the few moments it is inside, the storm and wintry tempest cannot touch it, but after the briefest moment of calm, it flits from your sight, out of the wintry storm and into it again. So this life of man appears but for a moment; what follows or indeed what went before, we know not at all.
--Bede, Ecclesiastical History of the English People II.13, trans. Bertram Colgrave and R. A. B. Mynors (ca. 750)
Archaeologists and anthropologists have done much to reveal the realities of life during the Middle Ages. Around the year 1000, for example, we can determine from Anglo-Saxon gravesites that life expectancy was very short, that infant mortality rates were very high, and that diseases that attacked the skeletal structure were very common. Diseases such as rheumatism, arthritis, and rickets were the rule rather than the exception in Anglo-Saxon England. Respiratory illnesses would also have been common, due in large part to the living conditions since most people lived in what can only be described as hovels: tiny one-room structures heated by a central fire with a central roof opening to allow some of the smoke to escape. During the worst of the winter months, the choking soot in the air combined with the stench of the livestock (brought indoors to keep from freezing) to make for enormously polluted air. At other times of the year, the air was filled with mold spores and mildew allergens as the floor seeped from a rising water table, rain poured in through the battered roof, and the very walls bled with moisture. Bitter drafts were a constant fact of life.
The famous passage from Bede's Ecclesiastical History of the English People given above, reporting the words of a member of Edwin of Northumbria's council when pressed about the question of converting to Christianity, is particularly useful here: not only is it a supremely exquisite metaphor for the temporal and tenuous nature of human existence, but the detail of a sparrow flying into and out of the king's great hall in the middle of a blizzard says much for living conditions in medieval Europe. Even the king of Northumbria lived with the bitterest of drafts coursing through his quarters from door to door.
The typical diet of an Anglo-Saxon consisted of meat (primarily small game and pigs), goose and hen eggs, assorted vegetables (frequently onions, cabbages, and carrots), perhaps some fish, cheese and butter made from sheep's milk, bread (mostly wheat and barley), and water or beer (wine on rare occasions, mead rarer still). Wild berries would have been a delight when in season, as would fruit. With a lack of refrigeration, however, the diet was deficient in Vitamin C for much of the year, especially during the winter, when a diet predominantly made up of salted meat would lead to symptoms of scurvy. A lack of Vitamin A and niacin undoubtedly led to common skin and eye problems, and smoky living conditions probably exacerbated both.
The daily life of an Anglo-Saxon did little to alleviate health problems. The life of a plowman, as related in Ælfric's Latin Colloquy (for the c.1000 Old English translation, see Murray McGillivray's hypertext version), gives an example daily routine in winter: "I go out at dawn, driving the oxen to the field and yoking them to the plow. There is no winter so harsh that I dare to stay at home; but with yoked oxen and share and coulter fastened to the plow, every day I must plough at least an acre for fear of my lord." Even when his voice is hoarse from shouting in the cold, the plowman must still fill the oxen's manger with hay, bring the animals water, and carry out their manure. In addition, wood had to be cut for the fire, ashes had to be cleaned out of the pit, repairs had to be made to the home, supplies needed to be procured, cooking and cleaning and mending had to be done. And all of it in clothing that was spare, damp, and worn from work.
It should not surprise us at all that medieval people were often in ill health. Tertian malaria (with a fever recurring every third day) was very common, especially in spring when mosquitoes swarmed out of the fens and marshes. The parasitic sheep liver fluke ran rampant through the population, causing liver abscesses. Dysentery, jaundice, pleurisy, pneumonia, and immune-crippling iron deficiencies were rife. Bouts of influenza were often fatal, and even the common cold could be a debilitating blow.
This picture of turn-of-the-millennium Anglo-Saxon England is not an idyllic one, and it is sad to note that life did not grow measurably better as the Middle Ages wore on. Viruses swept through the known world with terrifying frequency, as did bouts of plague and other fatal diseases. Most famous, of course, is the Black Death: an epidemic of bubonic plague that originated in Asia and followed the trading routes west to Europe, arriving in Cyprus in 1347. By 1349 it had reached as far as Scandinavia and Scotland, and by 1351 it was tearing through Russia. At least 25 million people died in the first wave -- a full quarter of the population of Europe. Taking into account subsequent waves of the plague, nearly half the population of Europe was lost to plague during this period of the late Middle Ages. Some idea of the devastation is provided by the account of Marchione di Coppo Stefani. His relation of the aftermath of the first wave of plague in 1348 Florence is simple, direct, and unflinching:
Now it was ordered by the bishop and the Lords that they should formally inquire as to how many died in Florence. When it was seen at the beginning of October that no more persons were dying of the pestilence, they found that among males, females, children and adults, 96,000 died between March and October.
--Marchione di Coppo Stefani, The Florentine Chronicle, rubric 635 (ca. 1380)
To combat and cope with these problems, medievals turned to their doctors. Then, as now, the primary role of the physician was in comforting the patient and providing encouragement that health could be restored. The idea of actually "curing" a disease, something which we are accustomed to, was still a new development at the time of World War II. Yet even today the physician is often more therapist than miracle-worker.
His life was gentle, and the elements
So mix'd in him that Nature might stand up
And say to all the world, "This was a man!"
--Shakespeare, Julius Caesar V.5.73-75 (1599)
Full image available La Bibliothèque nationale de France
Humoral theory is behind much of the physician's understanding of the body during the Middle Ages. A Hellenistic theory popularized by the works of the Greek Hippocrates, it dominated medicine until the nineteenth century. At its most basic level, this theory is based on the fact that all matter in the universe, including the human body, was thought to be built of the four elements: earth, water, air, and fire. The observant Hippocrates noted that blood separates into four liquids when removed from the body and examined: a pure red liquid mixed with white material, with a yellow-colored froth atop and a black substance that settles below. He and other ancient physiologists identified these four substances as the four principal fluids within the body, calling them humors (from the Latin umorem, "fluid"): black bile, phlegm, blood, and yellow bile. These humors were then assigned elements based on their perceived characteristics: phlegm is cold and wet so it is made of water, blood is warm and wet so it is made of air, and so forth. Though all humors originated in the liver as a by-product of digestion (food was "mined" four times: first for blood, second for phlegm, third for yellow bile, fourth for black bile), each humor was, in turn, associated to parts of the body where an abundance of that particular humor was likely to be found: phlegm in the lungs, yellow bile in the gall bladder, and so on. We can see this structure of the human body reflected in medieval art, like a fifteenth-century image from a manuscript of Bartholomew the Englishman's Book on the Properties of Things, now housed in France's Bibliotheque Nationale (Fig. 1).
If these humors (and thus the elements) were in balance within the body, the body was healthy. But if the body became unbalanced, illness would result. Thus an overabundance of phlegm, for example, caused lung problems; the body naturally tried to cough up the extra phlegm and restore balance. These humors, it was found, naturally ebbed and flowed during the year, so seasons were assigned to them. Winter, with its colds and smoke-filled hovels, naturally was thought to cause an abundance of phlegm. In addition, basic psychology could be attributed to this simple but elegant system: if you were angry you grew warm, you sweated and your face grew red as a direct result of your body producing too much yellow bile in the blood. The complexion of an individual (literally, the make-up of his humors) was thus often said to be in a person's face, a concept from which developed our modern use of the word "complexion" to denote facial make-up. Even dreams are tied to this system during the Middle Ages: too much red bile and you will dream of red things, too much black bile and you are likely to dream of black monsters and so forth (compare Chaucer's "Nun's Priest's Tale," lines 4120-26). The result of these theories was a set of associations that looked something like this:
Earth (cold, dry) Black bile Melancholic Spleen Autumn Prone to sadness Water (cold, wet) Phlegm Phlegmatic Lungs Winter Prone to apathy Air (warm, wet) Blood Sanguine Head Spring Prone to optimism Fire (warm dry) Yellow bile Choleric Gall bladder Summer Prone to anger
Even today, with the physiological theory of humors abandoned, the basic concepts are still with us in our vocabulary. We continue to speak of someone in an ill mood as being in "ill humor;" likewise, a lighthearted person might be said to be in "good humor."
Full image available at Princeton University
Another remnant of this basic system is in astrology. Based on the rationale that the heavens influenced the weather (among other things) and must therefore affect the human body, too, medieval thinkers figured that the signs of the Zodiac must be associated with certain elements and hence with certain humors. Thus a person born under a certain sign of the Zodiac was likely to be influenced by that sign to behave in a certain way. Further complicating the system was the association of specific parts of the body (where those certain humors were supposed to reside) to those signs of the Zodiac. A man born under the sign of Gemini, for example, was prone to be phlegmatic because Gemini was associated with water and thus with the humor of phlegm. The man was also likely to have either trouble or good luck (depending on your point of view) with his lungs since they are the home of his phlegm. By the Late Middle Ages, these Zodiac-body relationships had expanded to include almost every part of the body -- though why ankles, for example, were associated with Aquarius will forever remain a mystery. A good example of the Zodiac system at work can be found in medieval images of the Zodiac man, complete with labels denoting those parts of the body influenced by each sign (Fig. 2).
Bleeding the Patient Dry
I swear by Apollo the Physician, and Æsculapius, and Hygeia, and Panacea, and all the gods and goddesses. . . .
--Hippocrates of Cos, Oath of Medicine (ca. 400 BCE)
According to the humoral theory of illness, most health problems could be attributed to an excess of a humor. Alleviation of this excess would alleviate the illness. A physician might diagnose the patient based on any number of observations and factors: physical pains, time of the year, diet, exercise, urine sample, fecal sample, pulse, breath, or appearance. Sometimes a small blood sample would be taken, and diagnosis made based on the properties of the blood (how quickly it coagulated, did it layer or clot, was there too much black bile, etc.). The physician might then consult a leechbook (a medieval manual of medicine) in order to determine the course of action to be taken.
Full image available at Princeton University
For example, a fever, being an ailment with hot and dry symptoms, would be due to an excess of yellow bile. The solution to the fever would therefore be either to drain off excess yellow bile (probably by bleeding, see below) or to stimulate the production of yellow bile's opposite humor, phlegm (probably by prescribing something cold and wet, like an icy bath). Likewise, a phlegmatic individual might be given a special medicine (we might call many of these potions given their ingredients) that was hoped to act as an expectorant, encouraging the coughing up of phlegm, or told to wrap up in a warm bed and drink a lot of dry red wine. In other situations, a certain diet or means of exercise might be prescribed in order to eradicate excess humor or encourage the development of a particular humor. Drugs that caused diarrhea or vomiting were also popular solutions, as the emission of fluids from the body was perceived as a sign that the imbalanced humor was being expunged.
The medieval physician had a counteraction to any imbalance anywhere in the body, but our modern association with the concept of balancing humors is almost entirely caught up in the practice of bloodletting. Oddly enough, bleeding was not only a means of controlling the sanguine humor; as we've already seen, blood contains all four humors. In addition, however, every major organ of the body was thought to be associated with a specific part of the circulatory system (Fig. 3). Bleeding from a specific vein might drain off fluid from, for example, the gall bladder, thereby alleviating yellow bile from a choleric individual.
During the Middle Ages there were three main methods of bloodletting: leeching, venesection, and cupping. In leeching, the physician attached an annelid worm of the species Hirudo medicinalis to the patient, probably on that part of the body most severely affected by the patient's condition. These worms were called leeches because they were used extensively by Anglo-Saxon physicians. (The word for "doctor" in Old English is læce). The worms would suck off a quantity of blood before falling off. Venesection was the direct opening of a vein, generally on the inside of the arm, for the draining of a substantial quantity of blood. Cupping involved the application of glass cups over the skin. When heated, these cups would act as small vacuums, drawing blood toward and then through the surface of the skin. Regardless of the method used, the purpose was the same: alleviating the excess blood in the body in an effort to restore balance and health.
More information and images available at the Claude Moore Health Sciences Library, UVa
Given their understanding of the body, the practice of bloodletting made perfect sense. And, in many ways, it worked. Modern doctors continue to prescribe the use of leeches for certain medical treatments (though thankfully with less frequency than their predecessors in the Middle Ages), finding them vital in various procedures. A leech, for example, helps to reduce tissue congestion where arterial input is maintained but venous return is blocked or slowed, effectively acting as an extra vein to relieve a dangerous build-up of blood. As a result, so-called leech therapy is finding its way into numerous reconstructive surgeries such as digit and limb reattachment, skin graft procedures, scalp avulsions, breast surgeries, and even into the effective treatment of periorbital hematomas. Many of these procedures might not be able to take place without the medicinal use of leeches and their extraordinary ability to remove blood (one leech can draw off nearly 150 ml of blood over the course of 48 hours). In addition to preventing blood clots and treating tissue inflammation, certain compounds in leech saliva have been found by pharmaceutical researchers to kill certain strains of bacteria and even to relieve pain.
Full image available at the Wellcome Library for the History and Understanding of Medicine
Despite these modern uses of leeches, there is something about our own perceptions that makes us view the medieval use of bloodletting as horrifying. Perhaps we have all simply bought into the stereotype of medieval people as superstitious and frightfully inept. Perhaps we are so naive as to think that they blindly stumbled into the benefits of such practices whereas we determined their benefit through modern technologies and theories. Regardless, we cannot look back on the medieval practice of balancing humors as barbaric or ghastly. It was a practice based on the best information at hand, and one that brought relief (either physical or emotional) to many patients. And we must try to remember that bloodletting was by no means the only option for physicians, or even the preferred option. It was simply one of the many options available for bringing succor to the ailing.
Sometimes, of course, more drastic surgery was required. Broken bones, grievous wounds, terrible abscesses, and even things such as bladder stones might require surgical procedures (Fig. 4). It is well to remember that, generally speaking, surgery was conducted without anesthesia since most means of "putting a patient under" were as likely to cause death as anything else was. And surgery was not conducted in anything that would resemble a sterile environment since the concept of associating infectious disease with germs or bacteria was entirely unknown during the Middle Ages. Once again, leechbooks were often consulted for the correct means to deal with serious injuries or debilitating conditions. The image of the Wound-man (Fig. 5) was made for precisely this purpose: each possible wound was keyed to a description of how to treat it.
The Last Resort
Before all things and above all things, care must be taken of the sick, so that they will be served as if they were Christ in person; for He Himself said, "I was sick, and you visited Me" (Matthew 25:36).
--St. Benedict, Monastic Rule, chapter 36 (ca. 530)
Full image available at Princeton University
And sometimes, just as now, the physician could do nothing. So then, just as now, people would resort to totems, amulets, or the reciting of special charms that were thought to relieve illness by magical or miraculous means. And certainly one cannot deny the power of prayer for a people whose world (in this life and in the next) was far more intimately tied to the Church than our own. This aspect of medicine could be extremely important since sin was also thought to be responsible for certain inexplicable ailments or illnesses: leprosy, for example, was associated with the sins of lust and pride. Here again, however, we cannot condemn medievals for their stupidity or superstitiousness. True, the Black Death was thought by many in medieval Europe to be a punishment sent by God for the collective sins of the people. But similar arguments were made (and are still being made) about the AIDS epidemic. Given the razor's edge between life and death in the medieval world, it is only too understandable that religion should have a vital influence in all aspects of life. In this sense, medieval medicine was entirely holistic: body, mind, and soul could not be separated, so all required treatment.
May I never see in the patient anything but a fellow creature in pain.
--Maimonides, Oath of Medicine (ca. 1200)
Full image available at Princeton University
Medieval medicine was not primitive, simplistic, crude, or ignorant. Viewed on its own terms, it is a viable and logical system. The facts at hand for the medieval physician were few, and the authority of Classical writers like Galen and Hippocrates was difficult to contradict. It was only as the human anatomy began to be understood more thoroughly (the circulation of blood was not figured out until well into the sixteenth century) that substantial changes to ancient practices could be made. In particular, of course, dissection eventually proved to be a fount of information about the body -- prior to post-mortem examinations, most information was based on logic, the dissection of animals, and the examinations of wounds. But during the Middle Ages, the idea of conducting post-mortem examinations of the human body in order to learn more about its inner workings was largely anathema for both religious reasons (the body is a temple) and intellectual reasons (the very concept is repugnant). And even though dissections grew more frequent as the Middle Ages wore on (Fig. 6), such anatomical studies were rare even into the Renaissance (Fig. 7). The physician of the Middle Ages had little more than authority and his own experiences to guide him in his craft. We should not be appalled at the results of such practices, rather we should study them on their own terms and learn to appreciate them. And if the physician is to be judged by the ability to bring comfort to patients, we cannot think less of the medieval physician. For, without a doubt, the medieval physician played a vital and important social role as a caregiver to the sick, the wounded, and the dying.
Copyright © 2003 Michael Livingston
Michael Livingston holds degrees in History and in Medieval Studies, and he is currently pursuing a Ph.D. in English at the University of Rochester. In addition to a course on medievalism (focusing primarily on J.R.R. Tolkien), this spring he is teaching a seminar on medieval medicine at the University of Rochester School of Medicine: "Bleeding the Patient Dry: Medicine in the Middle Ages (not a practicum!)." His previous publications in Strange Horizons can be found in our Archive.
Adam, Robert, and Peter Zakrzewski. "Therapeutic Uses of Leeches: From the 'Annelids' of Medicine." University of Toronto Medical Journal 79 (2001): 65-67.
Cameron, M. L. Anglo-Saxon Medicine. Cambridge Studies in Anglo-Saxon England 7. Cambridge: Cambridge University Press, 1993.
Conrad, et al. The Western Medical Tradition 800 BC to AD 1800. Cambridge: Cambridge University Press, 1995.
Grigsby, Bryon. "Medical Misconceptions." 1999. ORB: the Online Reference Book for Medieval Studies. (Jan. 27, 2003).
Hunt, Tony. The Medieval Surgery. Woodbridge: Boydell, 1992.
Krzywicka, Maggie. Medieval Medicine. 2000. (Feb. 18, 2003).
Pollington, Stephen. Leechcraft. Anglo-Saxon Books, 2000.
Talbot, Charles H. Medicine in Medieval England. London: Oldbourne, 1967.