Are leeches harmful to humans?


Quick Answer

Leeches are not harmful to humans. In fact, they are quite helpful. Leeches do not draw enough blood from a human to cause any damage and have been used for thousands of years in the medical field for a variety of reasons, including their ability to help reattach body parts.

Continue Reading

Full Answer

Leeches produce an anti-coagulation agent that is transferred through their saliva. After a leech bites a human, this agent keeps the site of the bite from coagulating. The lack of coagulation allows the site to bleed out for hours after the leech has been removed. This allows oxygen to enter the blood through the wound, promoting vein re-growth and blood circulation. Leeches are invaluable in grafting and reattachment surgeries, which often involve tiny veins that are unable to be reattached by hand. The veins are kept from coagulating by attaching leeches to a grafting or attachment site, allowing existing veins to fuse and new veins to generate.

Leeches produce a natural anesthetic that allows them to bite without causing pain. While leeches on the surface of the skin are harmless and even beneficial, they should never be ingested. Humans should be cautious around them and ensure that they do not invade the cavities of the body, like the nose.

Learn more about Worms

Related Questions

  • Q:

    Where do worms come from?

    A: Experts say that most earthworms were imported from Europe to North America by settlers. To stabilize their ships, settlers loaded them with soil that cont... Full Answer >
    Filed Under:
  • Q:

    What is a flatworm?

    A: A flatworm is any member of the phylum Platyhelminthes, which is a group of flattened invertebrates that have soft bodies. There are different species of f... Full Answer >
    Filed Under:
  • Q:

    How do glow worms produce light?

    A: Glow worms produce light using a chemical reaction involving the chemicals luciferin, luciferase, ATP and oxygen. They use this light primarily to attract ... Full Answer >
    Filed Under:
  • Q:

    What do worms eat?

    A: The diet of a worm is based off its location, but worms traditionally eat everything from dead leaves to melon rinds and even cardboard. Studies show that ... Full Answer >
    Filed Under: