The truth about Leech Bite

Many people are afraid of leech bite because the wound needs up to 24 hours to clot. People are afraid that they may loose a lot of blood and die. Well, in many leech-bite cases, death is never the result. To control the fear of leech bite, there are truths we need to know.

When a jawed leech bites it holds the sucker in place by making its body rigid. Using its semi circular and many toothed jaws like minute saws, it then makes an incision in the skin and excretes a mucous from the nephropores (external openings from the kidney-like organs). This helps the sucker to adhere. A salivary secretion containing the anticoagulant and a histamine floods the wound and the leech relaxes its body to allow the blood to be ingested. This mixture allows the blood to flow and also prevents clotting once inside the leech. A bacterium in the gut of the leech assists the digestion of the blood, and it has been shown that the type of bacterium varies with the type of host on which the leech feeds. The bacterium also prevents growth of other bacteria which may cause the ingested blood to putrefy.

Now you see the results of leech bite, and because of these capabilities, leeches are used for therapy to cure many blood-related diseases in modern medication. You may have heard about leech therapy.


For over 2000 years, leeches were needlessly applied for many ailments as an adjunct to blood letting. Their use in Europe peaked between 1830 and 1850, but subsequent shortages led to a decline in their use. Today there is a real clinical application in that they are of great value to plastic surgeons when venous congestion of skin and muscle flaps is a problem. Leeches are treated in the same way as blood products and are reused only on the same patient. Medical use of leeches also includes treatment of black eyes, and hirudin is used in the treatment of inflammation of the middle ear. Hirudin is also being developed for experimental use as a systemic anticoagulant, and may prove useful in invitro blood sampling.

The presence of hirudin in the wound following a leech bite may cause oozing to continue for several hours. Although inconvenient, blood loss is not significant. Gut bacteria can cause wound infection. In the post-operative use of leeches this is closely monitored and dealt with by use of the appropriate antibiotic. There may also be a delayed irritation and itching after a bite. There appears to be no support for the theory that mouth parts left behind after forced removal of the leech causes this reaction.

So, can leeches transmit disease? There is no evidence to suggest that they do. The presence of trypanosomes (malarial parasites), in the gut of jawless leeches has been noted, but jawed leeches do not appear to be hosts. Allergy to leech bite has been reported. Further medical opinion should be sought, depending on the severity of the reaction. However, experienced therapists are needed to monitor leech therapy.


After knowing the truth about leech bite, it won't be a horror anymore. Indeed, it's a blessing for humankind to find another healing alternative for blood-related diseases. Wanna buy some leeches?