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If you'd like to make a suggestion, you can do so on Facebook and Instagram at morbid curiosity podcast on Twitter at morbidpodcast and on our website www.morbidcuriositypodcast.com In this episode, we'll be going into detail on medicinal bloodletting, the feeding process of leeches and their medical use, which can get quite graphic. So if that's not something you want to hear about, this may be a good episode to skip. Humans are fascinated by gore and violence, but even more so, the mysterious and unsolved. Interest in these disturbing and unpleasant subjects is called morbid curiosity and it has gripped hundreds of people throughout the ages.
I am one of those people. My name is Hallie and this is the morbid curiosity podcast. How often, in a period film or television show, has a doctor prescribed bloodletting or a course of leeches to an unwell character? I can think of two examples almost immediately.
The 1995 film Sense and Sensibility set in Regency Era England and the first episode of Blackadder II set in the Elizabethan era in England. While the Blackadder scene pokes fun at physicians of the past for prescribing bloodletting by leeches for every single ailment, the scene and sense and sensibility is more upsetting. As the modern audience knows, the character is very sick and wonders how bleeding is supposed to help. Bloodletting seems barbaric to us today, not only barbaric but illogical.
We can't see how the people of the past believed it to be useful, healthy or revitalizing. To us, it's debilitating, even deadly. Our views are based on modern science, which has proven that blood loss is quite detrimental to human health. It must have been obvious to people of the past that blood was essential to life.
They hunted, they spilled animal blood, and saw that large wounds result in blood loss and death. Therefore, we'd expect they would want to retain blood rather than drain it. But for much of Western history, bloodletting was thought to be a healer of all ills. From antiquity to the mid-19th century, it was the most common and most trusted surgical procedure.
Why this didn't change with the rise of the study of human anatomy is quite a mystery. It's been hypothesized that people of the past saw that other things were also needed to sustain life, such as food, water, and breath. Blood, and observed changes in it, became a way to determine how a person was, not just that they were alive. Bloodletting for the sake of health or medicinal bloodletting is an ancient therapy.
It developed alongside the idea that all disease is caused by tainted, impure, or an excess of blood that must be removed to regain health. The first documented references to bloodletting come from the Hippocratic corpus, a collection of medical documents dated to the late 5th early 4th century BCE, as well as an ancient Chinese body of medical literature called the Huang di-Niching, abbreviated as the nijing, which dates to between 475 BCE and 220 CE. In both bodies of work, bloodletting is mentioned, but does not feature as a cornerstone of medicine. The methods recorded by Hippocrates of drawing out the blood included phlebotomy, also known as venus section, which was the cutting of the veins with a sharp implement, as well as cupping, which used suction to draw blood to the surface of the skin.
Both of these processes were done in specific locations for specific symptoms. This type of focused bloodletting is called topological bleeding, as location matters. These locations were called flebs, and while some were anatomy-based, although the exact path of veins and arteries was unknown at this time, other locations were just believed to be connected to certain body parts by an imagined network of channels. The older parts of the nijing feature bloodletting more often than the newer parts, which focus more on acupuncture, a bloodless type of surgery involving needles.
Like Hippocrates, many of the bleeding sites mentioned in the nijing were near major arteries, but others were not. Physicians were advised that if any of these sites were misused, great harm could come to the patient. This fear of misusing these sites may well be why bloodletting later faded from Chinese medicine. It's also possible that this network may have inspired the complex network of acupuncture points that developed later.
Later Greek and Chinese texts diverge on bloodletting. Galen, the famous Roman physician, who wrote between 160 and 217 CE, no longer focused on specific locations, were bleeding by eight certain body parts. Where the blood came from mattered far less than getting it out of the patient. This is likely to impart to the spread and expansion of Hippocrates theory of the four bodily humors.
The humoral system of medicine, which was extended by Galen, quickly became the going medical theory in the second century CE in the Mediterranean, and lasted in most of the western world until the 17th century. Many perceived issues with blood could cause all sorts of symptoms, including mental symptoms. In the humoral system of medicine, four theoretical vital body fluids, blood, phlegm, yellow bile and black bile, existed in the human body, and any imbalance in them could cause disease. These humors also had associated temperaments or behavioral types.
Blood was believed to be associated with a sanguine nature, meaning enthusiastic, active and social, and was considered a moist and warm humor. Yellow bile was warm and dry, and in excess of it was thought to produce aggression. Black bile was dry and cold, and too much of it was thought to cause depression. The word melancholy actually derives from the Greek word for black bile.
Phlegm, which is not the same phlegm that we think of today, was a humor thought to be associated with apathetic behavior, and was considered to be a cold and moist humor. It was believed that ingesting different foods could produce different humors in a human body. Seasons of the year, periods of life, geographic regions, and occupations were also thought to influence the nature of the humors. Therefore, disease could be caused and treated by a change in diet, environmental circumstances, location, or by bleeding.
Having too much blood was especially considered to cause most disease. This excess of blood was called plethora, and it was linked to almost every ailment. Certain foods could cause it in some people, while not eating certain foods could cause it in others. If the excess of blood wasn't removed, it was thought that the blood could putrefy and cause inflammation or other diseases.
This is why removing small amounts of blood became a treatment for so many ailments, and why the location the blood was drawn from no longer mattered as much. Galen wrote three works on bloodletting, setting out the theory of how it worked, diagnostic evaluations, to determine how much to bleed a patient for their symptoms, and how often to bleed them. He prescribed bloodletting to relieve gout, arthritis, dizziness, epilepsy, melancholy, and even hemorrhaging. He stated that it was an essential remedy and a traditional one, which suggests it became widespread some time before he wrote.
The Hwangi by Xi Yi Nanjing, a medical text compiled during the late Han dynasty of China in the second century CE, contains no mentions whatsoever of bloodletting, so between Hippocrates and Galen, bloodletting grew in popularity in the Mediterranean, but faded in the east. These areas shared trade routes, but apparently medical ideas didn't travel as far as goods did. Avicenna, a Persian physician, modernly called the father of medicine, completed his canon of medicine in 1025 CE. In it, he further expanded upon the humors, reiterating that blood was the most important of all.
He described how to tell healthy from unhealthy blood, and that the blood becomes unhealthy due to changes in temperament or in excess of other humors. Medieval European physicians received knowledge of bloodletting and leeches from translations of Arabic authors like Avicenna. They believed these authors, as well as Greek and Roman authors, were medical authorities, so the tradition of bloodletting continued on. No other treatment was as popular in the Middle Ages.
Bloodletting was used to relieve nausea, fevers, constipation, insomnia, and anxiety. Healthy people were also blood prophylactically, or to prevent them from getting sick. At this time, the most popular form of bleeding was by venus section, using a tool called a lancet, which was a small, sharp, double-bladed instrument, or a flem, which was similar to a pocketknife, in that it had a number of small blades, all of which could be folded into a case. Bloodletting over a larger area often involved scarification, scraping the skin with a cube-shaped brass box containing multiple small knives, followed by cupping, which involved placing a dome-shaped glass over the skin and extracting the air from it by suction or heat.
Leeches were also used for bloodletting and usually involved them as in a leech, hyrudo-medicinalis. Use of leeches became hugely popular in the late 18th-early 19th century, especially in France and England, algo deeper into the use of leeches after the outbreak. By the 16th century, there was some debate over whether bloodletting was as useful as previously believed. Still, use of bloodletting continued.
William Harvey's 1628 discovery that blood circulated through a system of veins and arteries, as opposed to the previous theory that the system was one way, didn't alter support for bloodletting at first. With the introduction of scientific medicine by way of controlled clinical trials introduced in the late 1600s, seeds of doubt in the benefits of bloodletting began to sprout among the medical community. Even after the humoral system of medicine fell out of favor during the 17th century, bloodletting was still regarded as an effective treatment. It was often recommended by physicians, but the actual procedure was done by surgeons and barber surgeons.
The red and white striped pole of the barber is supposedly derived from the practice of bloodletting, with the red representing blood and the white representing bandages. By the 18th century, surgeons were referred to as leeches as they were the ones who took blood from their patients. The debate over whether bleeding was helpful or actually quite harmful also grew during this century. Dr.
Benjamin Rush, an American physician and one of the signers of the Declaration of Independence was one of the more exuberant proponents of bloodletting. He believed that all illnesses that produce fevers were due to, quote, an irregular, convulsive action of the blood vessels, end quote. Therefore, all therapies should be directed at calming this vascular over-excitement. He even created a new name for the aggressive bloodletting he prescribed, depletion therapy.
Dr. Rush removed extraordinary amounts of blood from his patients, causing them to faint and often blood them several times this way. Many other contemporary physicians referred to his practices as murderous. The beginning of the downfall of bloodletting came with Dr.
Pierre-Louis of Paris, an analytically-minded physician who sought to scientifically assess the effects of bloodletting. He examined 77 of his patients with acute pneumonia, comparing the health of those treated with bloodletting in the early phase versus the same treatment in the late phase of the illness. In his conclusions, he didn't condemn bloodletting, but he did state that it was far less effective than commonly believed. Despite the growth of this debate, in the 19th century, the use of leeches became all the rage when it came to bloodletting.
It's thought that, despite new anatomical knowledge, because the cure to disease was still unknown, bloodletting offered a sort of placebo effect for people seeking treatment for a disease that was at the time incurable. Whatever the reason, millions of leeches were harvested and used for medicine in the 1800s. Subsequent research conducted by microbiologist Louis Pasteur, bacteriologist Robert Koch and others in the late 1800s, early 1900s, confirmed that the new scientific methods were far better for the health of their patients and the use of bloodletting gradually diminished to a few select conditions. As a medical treatment, bloodletting continued to fade in the 19th and 20th century.
Today, its only real use is in the treatment of a few rare diseases, such as hemochromatosis, a genetic disorder characterized by excessive intestinal absorption of iron, resulting in a pathological increase in total body iron stores, which can disrupt normal organ function. This disease is treated by weekly to yearly bloodletting, also known as lobotomy. Unlike bloodletting, however, the use of leeches has continued to this day. Before we get into just what leeches are and how they were used for bloodletting and other medicine, let's pause for a word from our sponsors.
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Leeches, as you may have gathered, are carnivorous worms that feed on the blood of other animals, including humans. They fall into the phylum analytica, along with other segmented worms. They're quite interesting creatures, exhibiting many fascinating abilities in the form of secretions that allow them to do what they do. But there is a certain yuck factor as my high school biology teacher used to say, so if you're squeamish, be prepared to squirm.
Among their segments, leeches have 10 stomachs, 32 brains, 9 pairs of testicles, and several hundred teeth. Being carnivorous worms, leeches feed on other animals with most species, consuming blood by temporarily attaching themselves to a host and drinking its blood. Some species are quite picky and will only feed on certain animals, while others are less choosy and will even eat smaller invertebrates. Those that feed on blood often have blade-like jaws to slit holes into the skin of their host, while others use enzymes in their saliva to digest a hole into the skin.
The host usually can't feel this at all, as the leech also secretes an analgesic, numbing the area that they attach to. After the hole is made, leeches secrete another substance called hirudin, an anticoagulant, which deters the blood from clotting. They then ingest the blood of the host using a sucking motion. Most leeches don't harm the host by feeding on them and drop off once they're full.
Leeches exist in many habitats, but are most commonly found in freshwater ponds and streams in North America and Europe. The most common species used for medicine, hirudin medicine alles, can grow to around 5 inches or 12 centimeters in length when stretched out. Their dorsal surface, or their back, is black with yellow streaks, while their ventral side or stomach is grey with black spots. They have two suckers on either end of their body.
The anterior or front sucker contains the jaws, while the posterior or end sucker is used for movement, which has been described as creeping or crawling when on land and gracefully swimming when in water. Hungry leeches will rest at the edge of their habitat, usually upon. When they sense vibrations in the water, they swim toward the source with surprising accuracy. Once they are attached, they typically ingest between 5 to 15 milliliters of blood.
Some leeches can drink up to 9 times their own body weight, which will feed them for an entire year. The feeding process usually takes between 10 and 40 minutes. Once full, the leech loosens its grip and falls off the host. It won't feed again until its gut is completely empty, which can sometimes take up to 3 months.
The site of the bite may bleed freely for between 24 and 48 hours, causing the host to lose far more blood than the meal the leech consumed. If jaws were used to create the wound, usually a small bruise and a wide-shaped scar is left behind. As for leech reproduction, they are hermaphroditic and require another leech to produce offspring. The two creatures exchange sperm packets and then go their separate ways.
Most H-medicinalis aren't sexually mature until they are around 7 to 8 years old. One of the first recorded uses of leeches as a medical device comes from a medical poem by Nykander of Colophon, a Greek physician and poet in the 2nd century BCE. Another early mention comes from the Sushrata Samhita, an ancient Sanskrit medical text dating to some time between the 1st century BCE and the 6th century CE. It describes 12 types of leeches and their uses in the treatment of skin problems, sciatica and muscle pain.
There is evidence that the Egyptians use them too, which may have inspired the Greeks and Romans to do the same. Dioscorides, Galen and Pliny the Elder all mentioned leeches under the name Sanguisuga. Avicenna dedicated several pages of his canon of medicine to the uses of leeches and also described where to collect them. According to him, the perfect leech from medicinal use had to come from a clean water source.
The worm must not smell bad and must be kept in a container for a day before applying to a patient. It must also be squeezed before application to force it to expel the contents of its stomach. The leech and the site on the human where it was to be placed both had to be cleaned before application. Also, a thread should be sewn through the tail of the leech to make sure it could be removed if it was placed in an orifice such as a nose or anus.
The fear of a wandering leech was quite high at this time, and Avicenna gave several ways of removing them. If a leech was swallowed, it could be flushed out by having the patient drink saltwater and then vomit. If part of the leech was still visible, salt could be applied to its back to make it release its grip and then drag it out from the orifice using the thread. A leech that wandered into the anus could be removed with a saltwater enema.
Abdell Latif Al-Baghdadi, an Arabic physician and historian, also described the uses of leeches in the 12th century. His writings describe a more modern use for leeches as a cleaner of tissues and post-surgical aid. As time went on and bloodletting continued to be used, leeches grew to be thought of as a slower, less painful alternative to vena section, and were therefore favored by some physicians, especially for more delicate parts of the body and on young and elderly patients. As I said before, the 17th century is when leeches grew popular as a medical treatment.
This craze lasted through the 18th century and grew even more vast in the 19th century in Europe. In his 1776 book on the Diseases of Children, Nils Rosanne von Rosenstein, a Swedish physician and founder of modern pediatrics, described using leeches on child patients for difficult dental eruptions, tooth abscesses, scarlet fever, pleurisy, and inflamed eyes. In 1812, the first leech farm was established in South Wales in the United Kingdom. Victorian era Britain used around 42 million leeches a year for bloodletting purposes, and around one quarter of them came from this leech farm.
Even after leeches fell out of favor, this farm has continued and even grown in the modern era. More on that in a moment. Francois Josef Victor Brusset, a revered French physician, was one of the most influential advocates of leeching in France. He felt that leeches could be used to treat all diseases.
He applied between 10 and 50 leeches at a time to every patient he saw, using hundreds every day. He treated typhoid, syphilis, tuberculosis, worms, and mental disorders with leeches. Because of his influence, millions of leeches were imported into France. In 1827 alone, about 33 million leeches were shipped to Paris.
French noblewomen even wore dresses with embroidery patterns representing leeches. In 1831, physicians in Sweden, which was believed to have the richest source of leeches for medical purposes, tried to impose an embargo on their domestic supply of leeches, as their stock was quickly becoming exhausted due to exportation. The Swedish government declined, but did create a monitoring program to keep tabs on pond populations of leeches. Leech farming was even attempted to aid in keeping the population high.
By the late 19th, early 20th century, with bloodletting disproved as a treatment for most things, leeches too declined in popularity. Soon, leeches were only prescribed by so-called quack doctors, whose supplies came not from a pharmacy, but from leech women who caught the leeches by dangling their feet in local ponds. Still, into the 1930s, hospital pharmacies often had a small supply of leeches. These were kept in large glass jars filled with water.
Sand coated the bottom of the jar, and the water had to be changed once a week. The leeches were supposedly fed occasionally by medical interns who dipped their toes into the water. In this environment, the leeches could survive for around eight years. In the 1970s, leeches drew the attention of physicians once more, especially in plastic and reconstructive surgery, which was a growing field at the time.
The special secretions of leeches were perfect for re-attachment surgeries, such as the re-attachment of a lost finger or a skin graft, as the leeches could improve blood flow through suction and their anticoagulant properties. In 1984, the leech farm in Wales, now known as Bio Farm, moved closer to Swansea and began raising leeches again due to their re-introduction and growing popularity in medicine. The leeches are bred and raised in three large tanks and fed sheep's blood in sausage casings every six months. The leeches must also exercise twice a day by moving them around the tanks, causing them to swim.
The oldest leeches live in a UV-lit room, which aids in making them as sterile as possible, for the hospitals they'll be shipped to. Today, this farm supplies most hospitals in the world that use leeches as complementary medicine. Medical leech therapy, abbreviated as MLT, or hyrutotherapy, is done in some hospitals today. The use of leeches has been studied using modern scientific techniques for the treatment of various diseases such as inflammatory disease, osteoarthritis, and as a post-surgery re-attachment aid to increase blood flow to the re-attached item, as well as removing accumulations of blood, from areas where tissue has been transplanted or reattached.
When blood accumulates, the tissue may die before it has a chance to heal, therefore applying leeches to the area gives new capillaries time to grow across the sutures and restore blood circulation. It's been found that leeches secrete more than 20 bioactive substances, including hyrutin when they feed. These substances have various effects, including anticoagulant, analgesic, anti-inflammatory, and antimicrobial properties. It's believed that further study will reveal even more effects that are produced by leeches secretions.
There's no current consensus on the application and duration of MLT, but most physicians who use it suggest a maximum of four to five leeches be applied for a maximum of 68 hours. During this time, clinical monitoring and blood count must be done to make sure the patient isn't suffering any adverse effects, as it has been found that some people are actually allergic to leech secretions. To avoid infection and accidental blood transfusions, each leech is used only one time and is killed humanely using an alcohol solution afterwards. In a 2002 survey of 50 plastic surgery units in the United Kingdom, 80% had used leeches in the previous five years.
Leeches have made the difference between a successful reconstruction or re-attachment surgery and a failed one. While history and modern science has revealed that bloodletting is, for the most part, harmful to humans, leeches, once an instrument of bloodletting, have proven to be the opposite. They have shown their worth to modern medicine in the varied and unique secretions they produce. Still, the yuck factor remains, as they are slimy, blood-sucking worms.
This juxtaposition of usefulness and creepiness is why leeches continue to spark our curiosity. If you like the show, please share us on social media and please please please give us a rating on iTunes. Your shares and ratings help us reach new listeners and expand this wonderfully creepy community. Thank you to everyone who commented, suggested topics, shared MCP posts, liked or followed the MCP on Facebook, Twitter and Instagram and gave us ratings on iTunes.
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