Leech therapy is a traditional method that uses leeches to suck blood for therapeutic purposes.

Leech therapy, also known as hirudotherapy, is a method in which live leeches are attached to human skin to suck blood, thereby achieving a therapeutic or adjunctive therapeutic purpose. This practice has a long history, with records of its use in both Chinese and foreign traditional medicine. In traditional Chinese medicine, leeches are regarded as a medicinal material for breaking blood and dispelling stasis, and are believed to be usable for related conditions caused by blood stasis.

Its effects mainly come from the saliva secreted by leeches when they suck blood. Leech saliva contains active ingredients such as hirudin, which has anticoagulant properties and can improve local blood circulation, so it can be useful in some situations where blood congestion needs to be relieved.

In modern medicine, microsurgery sometimes uses quarantined and processed medical leeches to help relieve venous congestion in affected areas after digit replantation and flap transplantation, which is currently a relatively recognized use of leech therapy. In the field of traditional Chinese medicine, leech-related formulas and external treatment methods are mostly used for adjunctive conditioning in cases such as traumatic injuries and blood stasis with swelling and pain.

From an agricultural perspective, medical leeches belong to a category of specialty breeding. In some areas, leech farming is carried out to provide a source for the medicinal materials market and medical institutions. The breeding process has certain requirements for water quality, temperature, and feed, and requires a corresponding technical foundation; the experience of ordinary aquaculture cannot simply be copied.

It should be noted that leech therapy is not an all-purpose miracle cure, and some exaggerated claims about its effects online should not be readily believed. Improper operation may cause infection, allergies, or continuous bleeding, and people with coagulation disorders or weak constitutions are also not suitable for it. If there is a genuine need, it should be done at a regular medical institution by professionals; never catch wild leeches yourself and try it.