For thousands of years, physicians relied heavily on a single treatment for hysteria, heart disease and just about every other malady: bloodletting. The theory behind the practice changed often over time, but the practice itself remained much the same -- with doctors often bleeding patients until they were weak, pale and, sometimes, unconscious.
-- Elena Conis
In the beginning in Asia and the Mideast, patients were bled to release demons and bad energy. Later, in ancient Greece, they were bled to restore the body's balance of fluids, and even later, in medieval and Renaissance Europe, they were bled to reduce inflammation -- by then thought to be at the root of all disease.
In ancient times, leeches were sometimes used, but more often people used thorns or sharpened sticks, bones or shells to cut open a vein (a process known as venesection) or to make small incisions in capillaries just below the skin (known as scarification).
Their successors used lancets and fleams -- small double-edged blades that came with pocket-sized, often tortoiseshell carrying cases. They used vacuum cups of varying dimensions to draw blood to the surface of the skin and bleeding bowls to catch the fluid, released in amounts from a few ounces to a quart at a time.
By the time of the Renaissance, blood-letters (often barbers in Europe), had the practice down to a science of sorts. Zodiac charts determined the best times of year for letting blood from different parts of the body. Medical tomes distinguished between diverting blood flow (bleeding the right arm to staunch a bloody left nostril, for example) and encouraging it (bleeding the foot to draw menstrual blood down).
Practitioners throughout Europe routinely bled patients who could afford it in efforts to prevent sickness brought on by excess food, weather changes and wounds.
By the late 1700s, bloodletting was the treatment of choice in America too -- thanks to the efforts of Declaration of Independence signer and physician Benjamin Rush.
Rush, who believed that tension in blood vessels was at the root of disease, turned to bloodletting to treat victims of Philadelphia's devastating yellow fever outbreak in 1793. He favored a quart at a time, repeated several times over several days, and claimed the treatment sped his recovery when he contracted the disease.
Later that same decade, George Washington fell ill with laryngitis, and his physicians bled him heavily, one after the other. The president gave up more than two liters of blood during the procedures and died a day later. Historians dispute whether it was the loss of blood or other complications that actually killed him.
In the decades that followed, physicians began to realize that germs -- not an imbalance of fluids -- were at the root of cholera, flu and other illnesses. But bloodletting retained a few adherents into the 20th century, and even today some of its wisdom, however faint, is coming to light: Leeches are used to improve circulation and prevent clotting in some surgical patients.
In 2004, University of Chicago researchers found that some bacteria rely on iron in blood cells to survive -- leading some researchers to conclude that as an attempt to kill bacteria, letting blood out of the body may not have been such a bad idea after all.