Bloodletting in Monastic Customaries

Bloodletting in Monastic Customaries

By Sarah Matthews, University of Iowa

Paper give at the ‘Regimens of Health: Housebooks and Everyday Medicines’ session at the 45th International Congress on Medieval Studies (2010)

Matthews’ paper dealt with the practice of bloodletting, which she sees as one of the maligned and misunderstood aspects of medieval medicine. Bloodletting was widely practiced long before and after the medieval period, and was commented on and approved by ancient writers such as Galen (although he also cautioned against excessive bloodletting or having the procedure done while fasting). It was believed that a person’s health was maintained by a balance of humors, and that illness was caused by an imbalance in one’s body. Bloodletting, like┬ávomiting, was seen as a way of removing certain humors from the body.

The paper examined how bloodletting was practiced in monastic communities, particularly does in France, Germany and the Netherlands, such as Cluny. While the monastic rules of these places does not offer any information about the practice, their customaries do offer many details. Customaries were working guides for monks, offering them examples of how to deal with a wide variety of situations, including proper health care.

Several monastic customaries devote an entire chapter on bloodletting, revealing some interesting information. First of all, bloodletting was a routine practice done for healthy monks – you were not allowed to have a bloodletting if you were ill or at times were the monks would be fasting, such as Advent. ┬áThe monasteries also prohibited bloodletting during the harvest season when work requirements were much higher.

Therefore bloodletting was only practiced on healthy individuals. The customaries also noted that it was understood that in the few days after a bloodletting the patient would be weakened. To deal with this, the customaries suggested that the monk be given a few days off of work in order to rest, and be given extra food too – they give details on which extra kinds of food they should get in order to have them regain their strength quicker.

The bloodletting was done by the monks themselves – physicians do not seem to have been involved in doing this procedure. Older monks would show how to perform the bloodletting to younger monks, but little is revealed on the details of the procedure – for example, it is not known how much blood was taken, or what did they do with the blood.

The texts offer also little information on why bloodletting was practiced routinely – only one customary offers a couple of explanations, namely to decrease the “heat of desire” which perhaps refers to food or sex drive; as well as a spiritual reason – it could be seen as an imitation of Christ, who was bled during his crucifixion. The placement of the chapters on bloodletting does give us a clue, suggests Matthews, since they are often found between chapters on general health care and personal hygiene. Perhaps the monks believed that regularly bloodletting was a preventative measure to maintain health – Matthews does note that a recent study has found that men who undergo bloodletting do reduce their chances of becoming affected with heart disease as arteries face less pressure at being clogged.

Matthews also began her paper by noting just one example of how popular culture sees the medieval practice of bloodletting – this skit is from Saturday Night Live:

Sign up to get a Weekly Email from

* indicates required

medievalverse magazine