By Oliver Stewart, MD
Peer Reviewed
As physicians, we are trained to utilize the most up-to-date medical guidelines to guide our clinical decision-making process. In addition, many of us contribute to these guidelines and the academic community by publishing our own research studies in the hope of advancing medical knowledge. Today we often take this established, methodical approach for incorporating new medical knowledge for granted. However, this evidence-based approach to medical practice did not always exist. For the vast majority of medicine’s history, the practice of medicine was much more art than science. It is from these more laissez-faire times that the ancient art of bloodletting arose.
The art of bloodletting began over 3,000 years ago via the ancient Egyptians, and the practice spread through Europe during the Middle Ages, eventually peaking during the 19th century before gradually falling out of favor throughout most of the modern world [1]. The vast majority of medical scholars today agree that bloodletting harmed far more people than it helped. However, why was the practice so popular in the first place? In order to explain this phenomenon, one must consider the prevailing medical ideas that existed at the time, prior to the existence of randomized controlled trials or systematic reviews. Hippocrates, considered by most to be the “founder of modern medicine,” believed that humans were composed of four basic humours: blood, phlegm, black bile, and yellow bile [1]. He believed that in order for a human being to remain in optimum health, the concentrations of these four humours in the body must remain balanced in the appropriate proportions [2]. Galen, the ancient Greek who wrote some of Greece’s most well-known medical texts, expanded on Hippocrates’ beliefs by developing the concept of plethora, the idea that an excess of humours was the cause of most illness [3]. As a result, the recommended treatment intended to rid the body of the excess of a particular humour through purging, vomiting, starving, or bloodletting [3].
In its infancy, bloodletting was accomplished via the most primitive methods, including using sharp thorns or animal teeth [4]. Over time, more refined methods were developed, including specialized double-edged blade lancets, called flebotomes and spring lancets, which allowed physicians to open a patient’s vein without the application of manual pressure [4]. Bloodletting became such a popular phenomenon that even barbers, who served as pseudo medical providers during the Middle Ages, began to participate in this treatment [5]. Historians suggest that the classic red-and-white barber pole is linked to bloodletting, with red representing blood and white representing the tourniquet used to slow the bleeding [5].
At its peak, bloodletting was a phenomenon that was well-regarded by the medical community as a viable treatment strategy for almost any disease process. It was not a throwaway treatment given to individuals of reduced means, but rather a pervasive treatment strategy recommended to rich and poor alike. There are several famous cases of bloodletting, but perhaps the most poignant case for American audiences is that of our founding father and first president, George Washington. On December 13, 1799, a mere 30 months into his retirement, Washington began suffering from a cough, which quickly progressed to difficulty swallowing and a fever [6]. Over the course of the next 12 hours, several physicians were called upon and they attempted treatment modalities that included enemas and various types of tea [6]. In addition, they reportedly removed over 80 ounces (2.365 liters, approximately 40 percent of total blood volume) over the course of 12 hours [6]. On December 14, 1799, Washington succumbed to his illness [6]. While physicians and historians have later gone on to debate Washington’s ailment (possibly acute epiglottitis, streptococcal pneumonia, or Ludwig angina), it is almost certain that bloodletting did not help his condition.
Gradually, bloodletting began to fall out of favor as physician-scientists utilized the scientific method to conduct studies with increased validity. For example, in the early 19th century, French physician-scientist Pierre Charles Alexandre Louis evaluated the medical records of 77 patients with pneumonia and analyzed the duration of illness and mortality data for patients who underwent bloodletting, compared to those who did not undergo the procedure [7]. Although he did not fully condemn bloodletting, he stated that its effects were “less than has been commonly believed [7].” However, despite mounting evidence against the practice, bloodletting continued to be endorsed by behemoths in the medical field such as Sir William Osler, and was recommended in the 1923 edition of Principles and the Practice of Medicine [8].
Today we recognize that the “four humours” theory was completely incorrect, and the practice of bloodletting has been largely removed from modern medical practice. However, there are certain conditions in which therapeutic phlebotomy is considered effective. For example, hereditary hemochromatosis is a genetic disorder that results in increased intestinal iron absorption and iron deposition throughout tissues and vital organs [9]. Therapeutic phlebotomy is often conducted on these patients in order to remove excess iron from the bloodstream. Although no randomized controlled trials have evaluated the efficacy of phlebotomy in this patient population, observational data demonstrates that phlebotomy is associated with increased life expectancy in patients with hereditary hemochromatosis. For example, a 2001 study of 179 patients from Denmark demonstrated that patients who were adequately treated with phlebotomy (median iron removal of 14g) had a higher survival rate than those who were inadequately treated (mean survival rate of 16 years, compared to 4.5 years) [10].
Phlebotomy is also an effective treatment modality for Polycythemia vera, another genetic condition. This disease is characterized by bone marrow malfunction and affected individuals typically have increased total red blood cell mass [11]. In order to help reduce the risk of adverse cardiovascular events, one of the treatments for the disease is regular therapeutic phlebotomy [11].
In addition to the two more established diseases above, there is also novel research being performed surrounding bloodletting as a therapeutic modality. For example, a recent meta-analysis of seven studies encompassing 512 patients suggests that bloodletting may be an effective treatment in individuals with chronic urticaria [12]. However, the author admitted that evidence supporting the claim is scarce, and that higher-quality clinical trials are needed in the future [12].
Overall, the history of bloodletting is rich and fascinating. Although it has fallen out of favor for good reason, it is important to remember the lessons that the ancient practice taught us. Specifically, the history of bloodletting reminds of us of the importance of basic science research, and validating medical theories through clinical trials prior to implementing them in practice. The next time you walk past your local barbershop and see the barber’s pole standing outside, take a minute to reflect on how far the medical field has come, and look forward to its continued progression.
Dr. Oliver Stewart is a resident physician at NYU Langone Health
Peer reviewed by David Kudlowitz, MD, internal medicine, NYU Langone Health
Image courtesy of Wikimedia Commons
References
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- Jackson WA. A short guide to humoral medicine. Trends Pharmacol Sci. 2001;22(9):487-489.
- The Long, Respected History of Bloodletting. Duke Today. https://today.duke.edu/2000/02/blood218.html. Published 2000. Accessed July 26, 2019, 2019.
- Bell TM. A Brief History of Bloodletting. The Journal of Lancaster General Hospital. 2016;11(July 26, 2019).
- Nix E. Why are barber poles red, white and blue? A&E Television Networks. Published 2014. Accessed July 26, 2019, 2019.
- Markel H. Dec 14, 1799: The excruciating final hours of President George Washington. PBS. https://www.pbs.org/newshour/health/dec-14-1799-excruciating-final-hours-president-george-washington. Published 2014. Accessed July 25, 2019, 2019.
- Morabia A. P. C. A. Louis and the birth of clinical epidemiology. J Clin Epidemiol. 1996;49(12):1327-1333.
- Bloodletting. UCLA Library: BIomedical Library History and Special Collections for the Sciences. https://web.archive.org/web/20120313034620/http://www.library.ucla.edu/specialcollections/biomedicallibrary/12193.cfm. Published 2012. Accessed July 26, 2019, 2019.
- Schrier SL, Bacon BR. Management and prognosis of hereditary hemochromatosis. UpToDate. https://www.uptodate.com/contents/management-and-prognosis-of-hereditary-hemochromatosis?search=hemochromatosis%20treatment&source=search_result&selectedTitle=1~106&usage_type=default&display_rank=1. Published 2019. Accessed July 26, 2019, 2019.
- Milman N, Pedersen P, a Steig T, Byg KE, Graudal N, Fenger K. Clinically overt hereditary hemochromatosis in Denmark 1948-1985: epidemiology, factors of significance for long-term survival, and causes of death in 179 patients. Ann Hematol. 2001;80(12):737-744.
- Tefferi A. Prognosis and treatment of polycythemia vera. UptoDate. https://www.uptodate.com/contents/prognosis-and-treatment-of-polycythemia-vera?search=polycythemia%20vera&source=search_result&selectedTitle=2~101&usage_type=default&display_rank=2. Published 2019. Accessed July 26, 2019, 2019.
- Yao Q, Zhang X, Mu Y, Liu Y, An Y, Zhao B. Bloodletting therapy for treating patients with chronic urticaria: A systematic review and meta-analysis protocol. Medicine (Baltimore). 2019;98(7):e14541.