Bloodletting (הקזת דם) was a very commonplace medical procedure in the Mishnaic times (see Shabbos 129). It is widely accepted that the ancient healers believed that:

"... many diseases were caused by plethoras, or overabundances, in the blood... "Bleeding" a patient to health was modeled on the process of menstruation. Hippocrates believed that menstruation functioned to "purge women of bad humors". During the Roman Empire, the Greek physician Galen, who subscribed to the teachings of Hippocrates, advocated physician-initiated bloodletting... The Talmud recommended a specific day of the week and days of the month for bloodletting... (WIKI ibid)"

Rambam started to treat the bloodletting with more caution (Deos 4,14):

"לא ירגיל אדם עצמו להקיז דם תמיד, ולא יקיז דם אלא אם היה צריך לו ביותר; ולא יקיז לא בימות החמה ולא בימות הגשמים, אלא ביומי ניסן ומעט ביומי תשרי. ומאחר חמישים שנה, לא יקיז כלל. ולא יקיז אדם דם וייכנס למרחץ, ביום אחד; ולא יקיז וייצא לדרך, ולא ביום שיבוא מן הדרך. ויאכל וישתה ביום ההקזה, פחות ממה שהוא רגיל; וינוח ביום ההקזה, ולא יתעמל ולא ייטייל".

We also know that hurting oneself is a transgression, and today the widespread bloodletting would be forbidden after proven seriously wrong. The Sages themselves saw a great danger in it.

I wonder if the Sages' practice of bloodletting was based purely on the medical customs of the leading "scientists" of their times, or had some Jewish traditional roots?

Please notice, this question is not about the benefits/dangers of bloodletting, but about its origin.

  • Why do you wonder about bloodletting and not the myriads of other forms of unsound medical advice mentioned by Chazal? – Double AA Mar 6 at 14:05
  • @DoubleAA I think BL is the most common and the most recognized with the Rabbis. Maybe there Is a medical tradition from Moses that we're unaware of. – Al Berko Mar 6 at 14:10
  • From: rasmussen.edu/degrees/health-sciences/blog/… - 2. Giving blood can reduce harmful iron stores One in every two hundred people in the U.S. is affected by a condition called hemochromatosis and most don’t even know it, according to Patenaude. Hemochromatosis is a disease that causes an iron overload and is labeled as the most common genetic disease among Caucasians by the Mayo Clinic. – Loewian Mar 6 at 14:45
  • 1
    3. Giving blood may lower your risk of suffering a heart attack Donating blood at least once a year could reduce your risk of a heart attack by 88 percent, according to a study conducted by the American Journal of Epidemiology.* This relates to the iron issue again, says Dr. David Dragoo, healthcare expert at Money Crashers. – Loewian Mar 6 at 14:47
  • 1
    IIRC Maharal held that it’s forbidden to quote medical advice from the Gemara because it’s probably wrong. – DonielF Mar 6 at 15:46

You must log in to answer this question.

Browse other questions tagged .