The use of medicinal leeches is as old as the Pyramids. Records indicate that Egyptians used leech therapy more than 3,500 years ago, and leeches (often mistakenly credited as cobras) are included in the hieroglyphics painted on the walls.
The tombs of Egyptian pharaohs contained pictures of leeches, and descriptions of leech medical treatments appeared in ancient Greek and Roman texts.
The popularity of leeches in Europe in the 18th and 19th centuries caused them to become scarce. Leech therapy was used to treat a wide range of conditions.
Herophilos (335-280 BC) was a Greek physician who was the first scientist to perform scientific dissections of human cadavers systematically and was deemed the first anatomist. Hippocrates (460BC-370BC), another Greek physician, is referred to as the “father of medicine.” He was the first physician to reject superstitions, legends, and beliefs that credited supernatural or divine forces causing illness.
Both physicians used medicinal leeches, amongst other methods, to remove blood from a patient to “balance the humours.” The four humours of ancient medical philosophy were blood, phlegm, black bile, and yellow bile.
The belief at the time was that these four humours must be kept in balance for the human body to function properly. Any disease or illness was thought to result from an imbalance of these humours. The dominant humour was believed to be blood.
However, Aelius Galenus (AD 129 – 200), a Greek physician, surgeon, philosopher, and the most accomplished medical researcher of the Roman era, introduced bloodletting to Rome. His theories dominated and influenced Western medical science for well over a millennium. Of the four humours,
Galen believed that blood was the dominant humour and the one in most need of control. Romans were the first to use the HIRUDO name for leeches.
Leech therapy, or hirudotherapy, survived the fall of the Roman Empire and remained popular throughout the Middle Ages. Over the centuries, it remained integral to treating diseases and illnesses worldwide. Bloodletting in its various forms was especially popular in the young United States of America.
Dr Benjamin Rush, a signatory of the Declaration of Independence, saw the state of the arteries as the key to disease, recommending higher-than-ever levels of bloodletting.
Sometimes, “bloodletting” was overdone; it worked so well in so many cases some tried to use it for everything. At the beginning of the 1800s, French physician Poliniere asked, “Leeches – immense good or terrible scourge?”
Dr Henry Clutterbuck, lecturing at the Royal College of Physicians, stated in 1840, “blood-letting is a remedy which, when judiciously employed, is hardly possible to estimate too highly.”
Indeed, by the mid-1800s, the demand for leeches was so high that the French imported about forty million leeches yearly for medical purposes. England imported six million leeches a year from France alone in the next decade since the leech production from their farm near Oxford was insufficient. And it wasn’t just Europe – there was an explosion in the use of leeches in Asia and the Middle East.
The 20th Century
With the advent of antibiotics in the mid-20th century, leeches fell out of favour. But not for long. In the second half of the 20th century, leeches came back with the advent of microsurgeries such as plastic and reconstructive surgeries. In operations such as these, one of the biggest problems is venous congestion due to inefficient venous drainage.
This condition is known as venous insufficiency. If this congestion is not cleared up quickly, the blood will clot, arteries that bring the tissues their necessary nourishment will become plugged, and the tissues will die. It is here where the leeches come in handy. After being applied to the required site, they suck the excess blood, reducing the tissue's swelling and promoting healing by allowing fresh, oxygenated blood to reach the area until normal circulation can be restored. The leeches also secrete an anticoagulant (known as hirudin) that prevents blood clotting.
Medical research and the use of leeches never stopped in some parts of the world, especially in Germany and Russia. So it is little wonder that both countries achieved the highest level of research on medicinal leeches, and Russia became the world's biggest producer of Hirudo Medicinalis.
The popularity of leech therapy began centuries ago when little research or scientific facts were available to back up the benefits – people just knew it worked. Today, however, we have proven facts and studies of the numerous advantages of using leech therapy.
Today leeches are on the cusp of not only enjoying a revival for known health benefits, but there are constant discoveries based on thorough medical research about the positive effects of the substances medicinal leeches introduce into the human body (and animals as well!) during the hirudotherapy treatments.