Bloodletting, one of the oldest medical practices, originated in ancient Egypt and spread through Greece, Rome, and eventually to Europe. Based on the humoral theory that health depended on a balance of four bodily fluids—blood, phlegm, yellow bile, and black bile—it was believed that illness resulted from an excess of blood, or "plethora." To restore balance, practitioners would intentionally open a vein to drain blood. While early methods might have involved sharpened wood or stone, the fleam emerged as a specialized bloodletting tool, particularly popular from the 17th to 19th centuries. These instruments often featured multiple, fixed blades, sometimes folding into a case, and were used to make incisions, typically in the forearm or neck veins, often by placing the fleam over the vein and striking it with a small stick to achieve a quick and clean cut. Despite its widespread and long-standing use for a vast array of ailments—from fevers to epilepsy—bloodletting rarely provided actual benefit and often caused harm, leading to its eventual decline in mainstream medicine by the late 19th century as scientific understanding of the human circulatory system advanced.