Phlebotomy is the medical procedure of drawing blood from a patient for diagnostic or therapeutic purposes. The term originates from ancient Greek, combining phlebos (“vein”) and tomia (“cutting” or “incision”). This etymology reflects the action of making an incision into a vein to collect blood. The process of blood collection has different names depending on the context, including clinical, conversational, or historical terms.
The Modern Term: Venipuncture
The most accurate and clinically used synonym for phlebotomy is venipuncture. This term refers specifically to the physical act of puncturing a vein with a needle. Venipuncture is the foundational technique used to obtain blood for various purposes in healthcare settings.
The primary function is to collect samples for diagnostic testing, allowing clinicians to analyze blood components or monitor a patient’s health. It is also the method used for collecting whole blood during donation drives. In some cases, venipuncture establishes intravenous (IV) access for administering fluids or medication.
While venipuncture describes the specific act of accessing the vein, phlebotomy is the broader term encompassing the entire process, including patient identification and sample handling. Conversationally, the procedure is often called a “blood draw” or “taking blood.”
Historical Practice: Bloodletting
Historically, the practice of drawing blood was known as bloodletting, which represents an archaic synonym for phlebotomy. This ancient practice was used therapeutically, based on the Hippocratic theory of balancing the body’s four humors—blood, phlegm, black bile, and yellow bile. For centuries, physicians believed that removing excess blood could cure or prevent a wide range of illnesses.
This historical form of phlebotomy, often called venesection, was performed using tools like lancets or, less commonly, by applying leeches. The intent was not diagnostic but rather a treatment to restore balance within the patient’s system. The discovery of the circulatory system in the 17th century and advances in modern medicine led to the discontinuation of bloodletting as a general therapeutic practice.
Today, the term bloodletting is considered a historical reference, as its therapeutic goal is no longer medically sound for most conditions. However, a modern version, known as therapeutic phlebotomy, is still used to treat specific blood disorders like hemochromatosis and polycythemia vera. In these cases, controlled removal of blood is performed not for balancing humors but to reduce excess iron or red blood cells.