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Story of Blood-Letting

As we explore current autism interventions, we have remarked on the fact that "folk wisdom" can lead to scientifically proven treatments...or not.  For an example of a folk practice that became an "evidence-based" malaria treatment so powerful it changed world history, see Story of Quinine.  The story below, on the other hand, is our example of a widespread practice, believed in by patients and practitioners alike, that was ultimately discredited.

Blood-letting was the intentional practice of withdrawing an amount of blood -- sometimes a large amount -- from a patient. It was believed to be “a tried and true remedy” for “fevers, inflammations, a variety of disease conditions and, ironically, for hemorrhage.”1

Originating in ancient Egypt and Greece, blood-letting was practiced for over 2,500 years by priests, healers, barbers, apothecaries, or physicians, depending on the era. It was based on the belief that an imbalance in one of the four fluid substances of the body, or “humors,” caused illness. Blood was one of these essential substances. 2   Relieving the patient of some excess blood, therefore, was thought to bring that “humor” back into balance. All sorts of instruments were created to aid in the process, from sharp knives for cutting into veins (lancets and fleams) to “cups” (which used suction to bring blood to the surface of the skin). According to this “four humors” model of belief, it all made perfect sense.

Bleeding was as trusted and popular in ancient days as aspirin is today. The Talmudic authors laid out complex laws for bloodletting. Medieval monks bled each other several times a year for general maintenance of health. Doctors devised elaborate charts indicating the most favorable astrological conditions for bleeding.

It wasn’t until well into the 19th century that people began to question the value of bloodletting. Scientists such as Louis Pasteur, Joseph Lister, and Robert Koch showed that germs, not humors, were responsible for disease. Furthermore, medical statisticians tracking case histories began to collect evidence that bloodletting was not effective. Eventually, the practice died out.”  3

Clearly, a treatment can be practiced for a very long time, believed in by healers and patients alike, despite the fact that it doesn’t really alleviate or cure anything. It can even be dangerous. George Washington, the first President of the United States, was bled to treat severe laryngitis in 1799 and died shortly thereafter. Of this incident, one medical historian writes:

“Today we find the removal of about eighty two ounces of blood (about five pints or units of blood) from a sick patient in less than sixteen hours to be incredible. However this was the method of treatment being taught in those days. It was the treatment of choice for many diseases and the complications of using this method were not comprehended by the physicians of that day.”  4

It is important to keep in mind that well loved remedies do not always have a basis in fact. They do not always actually address underlying causes and processes to cure or heal. In truth, we coping with Autism Spectrum Disorders have a great deal to be cautious about when evaluating treatments and therapies. Are we being sold a product that does very little except line the pockets of some snake-oil salesman? Are we holding onto practices that don’t really work out of desperation and because they give us some small measure of hope?

Please note: it is not just parents and patients who can be wrong in their beliefs. So can practitioners. Physicians believed in bloodletting, just as psychiatrists once believed bad mothers made children autistic. (See Refrigerator Mothers – A Discredited Theory --scroll down; it's the last entry on the page). Our words of caution are not just for parents, but for everyone.

Again, it is high quality research upon which we must depend, physicians, psychiatrists, educators, therapists, and parents alike. The goal of the IAN project is to facilitate such research, and as quickly as possible.


  1. UCLA Louise M. Darling Biomedical Library. (2002). Bloodletting. UCLA Biomedical Library History & Special Collections. Retrieved 2/6/07 from
  2. Seigworth, G.R. (2002). A brief history of bloodletting: Bloodletting over the centuries. PBS website: Red Gold – The Epic Story of Blood. Retrieved on 2/6/07 from
  3. Educational Broadcasting Corporation. (2002). Bloodletting. PBS website: Red Gold – The Epic Story of Blood. Retrieved 2/6/07 from
  4. Wallenborn, W.M., (1997). George Washington’s terminal illness: A modern medical analysis of the last illness and death of George Washington. The Papers of George Washington. Retrieved 2/7/07 from


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