Leech Therapy 1825 – Bloodsuckers

Although bloodletting with leeches for medical purposes has existed in Europe and Asia for thousands of years, its original purpose was linked to beliefs not accepted by modern science. For example, ancient medicine sought to balance the body's four main fluids: blood, phlegm, yellow bile and black bile. Leeches were therefore thought to restore this fluid balance by removing blood.

The medical use of leeches in Europe peaked when French physician François Broussais argued that "almost all diseases are based on inflammation and most diseases can be treated using leeches". This period is known as the Broussaisian era. Leeches became so widely used that some doctors likened the practice to vampirism. Using several dozen leeches in a treatment session was common, and millions were consumed each year in France, England and Germany.

In 1825, a representative addressing the French parliament said that doctors were driving farmers to their "graves" by overusing leeches, and that leeches had "shed more blood than many ruthless dictators". Drawing attention to this situation, he argued that excessive medical use of leeches must end. This call illustrates how dangerous and harmful the excesses of the period had become.

In France in 1828, approximately 100 million leeches a year were used. Demand exceeded supply, and leech prices became exorbitant. Leech farms were everywhere because leeches were used to "cure" everything from obesity to mental disorders.

The birth of modern medicine ended the conspicuous leech craze of the Broussaisian era. However, from the 1980s, medicinal leeches (such as Hirudo medicinalis) began to be used successfully after reconstructive plastic surgery (such as tissue and limb transplants). They are used especially to relieve venous congestion in ear or finger reattachment operations. Venous congestion occurs when blood accumulates in an area before veins have had a chance to regrow.

The leech's mouth is applied to the skin, releasing anticoagulants (such as hirudin), vasodilators (blood vessel dilators) and anaesthetic substances from its saliva. The leech removes about five millilitres (a teaspoon) of blood, and after it is removed, blood continues to flow beneficially for several days. This reduces the accumulation of blood and pressure, allowing time for veins to re-form.

Description of the article image: A man applying leech therapy to another man

Historical figures mentioned in the article: François-Joseph-Victor Broussais (1772–1838), John Brown (1810–1882)

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