Phlebotomy is the act of drawing or removing blood from the circulatory system through a cut (incision) or puncture in order to obtain a sample for analysis and diagnosis. Phlebotomy is also done as part of the patient's treatment for certain blood disorders.

Phlebotomy is part of treatment (therapeutic phlebotomy) for several diseases such as polycythemia vera, a condition that causes an elevated red blood cell volume. Phlebotomy is also prescribed for patients with disorders that increase the amount of iron in their blood to dangerous levels, such as hepatitis B, and hepatitis C. Patients with pulmonary edema (fluid in the lungs) may undergo phlebotomy procedures to decrease their total blood volume. Phlebotomy is also used to remove blood from the body during blood donation and for analysis of the substances contained within it. Patients who are anemic or have a history of cardiovascular disease may not be...