Phlebotomy Definition and History
Phlebotomy is the process of obtaining blood from a vein. In the old days, this was done by incising or cutting a vein and just letting the blood flow into a container. Today phlebotomy is done with much more sterile condition and also with much care by puncturing a vein with a needle. It is often done in order to obtain blood for diagnostic tests or to remove blood for treatment purposes to relieve the iron overload in hemochromatosis.
Phlebotomy or bloodletting-as it was called back in the days is one of the oldest medical practices among diverse ancient people such as the Greek, Egyptians and Mesopotamians. In Greece, bloodletting was in use around the time of Hippocrates who makes references bloodletting but in general relied on dietary techniques. Erastistratus, however, theorized that many diseases were caused by plethoras, or overabundances, in the blood, and advised that these plethoras be treated, initially, by exercise, sweating, reducing food intake, and vomiting. Herophilus a Greek physician advocated bloodletting. Archagathus, one of the first Greek physicians to practice in Rome, practiced phlebotomy extensively and gained a most sanguinary reputation.
The popularity of bloodletting in Greece was reinforced by the ideas of Galen, a well known Greek physician after he discovered the veins and arteries were filled with blood and not air as was commonly believed at the time. There were two key concepts in his system of bloodletting:
- Blood was created and then used up, it did not circulate and so it could ‘stagnate’ in the extremities.
- Humoural balance was the basis of illness or health, the four humours being blood, phlegm, black bile, and yellow bile these are closely related to the four Greek classical elements of earth, air, fire and water.
Galen believed that blood was the dominant humour and the one in most need of control. In order to balance the humours, a physician would either remove ‘excess’ blood or plethora from the patient or give them an emetic to induce vomiting or diuretic to induce urination. Galen created a complex system of how much blood should be removed based on the patient’s age, constitution, the season, the weather and the place. He linked different blood vessels with different organs, according to their supposed drainage. For example, the vein in the right hand would be let for liver problems and the vein in the left hand for problems with the spleen and the more severe the disease; the more blood would be let. Fevers required copious amounts of bloodletting.
Though Galen contributed the turning point in bloodletting there were also contributions from the Talmud, Islam, Christians, Arabs and others. Bloodletting lost favor in the 19th century and today we have phlebotomy which is a much safer procedure.