It is likely you have tried a few home remedies when you were ill. Perhaps some hot tea with lemon and honey, or a saltwater gargle to soothe your sore throat. I’m sure when you were concocting your remedy that the thought of leeches never entered your mind. And yet bloodletting was the most common practice performed by a physician until the late 19th century. Leeches have been used for bloodletting for thousands of years, and records indicate that the Egyptians used leech therapy over 3,500 years ago. Leech therapy was a common practice and used throughout the world. Of course bloodletting was also done by cupping and cutting, but for now we shall stick with the leeches.
In the 16th century, apothecaries sold leeches, both to physicians and to patients. Leeches were gathered in the spring by netting them in the fresh waters or by making yourself their meal and wading into the water with bare legs.
By the 18th century, leeches were a commodity, with the prices of leeches fluctuating from 25 to 50 cents apiece, which made them too expensive for the lower classes. Leeches underwent a kind of golden age in the early 19th century, as a type of cure all, and although this craze was centered in France, the demand for leeches happened throughout Europe and Asia. It was said that the leech farms were not able to keep up with the high demand. In 1833, over 41,500,000 leeches were imported into France, with only 9-10 million exported. A decade later, England imported six million leeches in one year from France, since their own leech production was insufficient.
Leeches were used for dentistry in 1817. When placed onto the patient’s gum, these water worms can drain an abscessed tooth.
To apply a leech: according to author Kristine Hughes in Everyday Life in Regency and Victorian England.
Leeches must be kept out of water for a half an hour before applying. The skin they are applied to must be washed and rubbed dry. A little sweetened milk will make them bite. When placing them on the patient, put the tapering end, which is their mouth, against the patient. Do not pull off leeches. They will naturally fall off when they are done. Never put leeches directly over a vein. A leech will drink blood weighing as much as itself within 15 minutes and consume between 2.5-5.5 grams of blood. Leech bites were bathed in cold water and covered with linen. If the bleeding doesn’t stop, then vinegar, silver nitrate, and hot wires were applied. Fed leeches were often put onto a plate of salt where they’d proceed to vomit the blood they consumed.
Leeches leave visible scars, which is why the smaller variety was popular to use of the face and neck. Leeches can be used over and over again, however a leech used on an infected person could transfer disease to another. The species Hirudo medicinalis has three jaws with approximately 100 sharp teeth on each outer rim. The saliva carried by the leech renders the bite virtually painless.
By the end of the 19th century the golden age for the leech had reached its end.
Leeches made a comeback in the 1980’s and are still used today, yet only under certain circumstances. The Federal Food and Drug Administration consider leeches to be medical devices. The leeches most commonly used for healing are Hirudo medicinalis, the European medicinal leech species. There are more than 600 species of leeches identified, but only 15 of the species are used for medicinal purposes. They are particularly useful in reattaching fingers and attaching flaps of skin in reconstructive surgery because they reestablish blood flow. Leeches can clear up congestion to prevent blood clots and prevent tissue from dying. Leech saliva contains an active anticoagulant component protein called hirudin. We now use this protein through laboratory methods called Recombinant DNA, which is a way used to bring together genetic material from multiple sources, creating sequences that could not otherwise be found in biological organism. There are also poisonous leeches that are green in color and they are known to cause fever and paralysis, don’t use these.
Although in the 21st century we may now find this practice abhorrent or consider the treatment from an uninformed era, this is simply not true. It is easy to understand why people and physicians of ancient times found this method effective, because sometimes bloodletting had the right results. If a person suffered from hypertension, and leeches were applied, the patient’s blood pressure would drop due to the reduction in blood volume, and in this case, the leeches were beneficial. Leech therapy was used for a wide range of symptoms, from headaches to ear infections and melancholia to fever. And bloodletting was believed to help patients balance the body’s humors, such as phlegm, blood, or yellow and black bile. Of course over time we learned that bloodletting was often damaging to the patients. In 1828, Pierre Charles Alexandre Louis was one of the first physicians to openly criticize bloodletting for the treatment of disease. In his research he found 44% of his pneumonia patients died if they were bled in the first four days, compared with 25% who were bled later in their illness. He deduced that bloodletting was useless in treating pneumonia. We know that bloodletting could lead to the patient’s death, case in point, the first President of the United States, George Washington had died in part from a bloodletting procedure gone wrong, seemingly five pints of blood were removed from him in less than sixteen hours.
By nineteenth-century standards, thirteen pints of blood taken over the space of a month was a large amount, but not an exceptional quantity. The medical literature of the period contains many accounts of bloodletting procedures-some were successful, some were not. Today it is well established that bloodletting is not effective for most diseases. Indeed it is often harmful, since it can weaken the patient and facilitate infections. With the backing of modern science, we have come to realize in fuller detail how these aquatic worms can provide improvement to our health and lives. In some instances, these bloodsuckers are very useful.
Special thanks to John M. Hyson, Leech Therapy: A History and White McKenzie Wallenborn, M.D, Papers of Washington.