Leeches are invertebrates, with slender, segmented, moist bodies, similar to worms. Leeches come in three varieties: land leeches, freshwater leeches, and marine leeches. While the word “leech” usually brings to mind visions of slimy little blood suckers, most leeches do not actually rely on human blood, but rather prey on small insects and other invertebrates. Of course, many leeches do survive by attaching themselves to a human host, drinking the blood; in these cases, people often want to remove these leeches. But first, it is important to understand how the leech works, and how to properly remove it.
To most people, leeches are unattractive and scary, belonging in horror movies; certainly, the idea of becoming a snack to a leech is unappetizing, to say the least. But despite the distaste that most people feel for leeches, these slimy creatures are not very dangerous. In fact, throughout thousands of years of global history, leeches have been used in bloodletting procedures which were thought to release things such as toxins or evil spirits.
Aside from ancient bloodletting, the most common way that people encounter leeches is by hiking through leech infested tropical forests, or wading through leech infested waters. In rainforests, land based leeches can be picked up while walking through brush and leaves, and sometimes will even drop down from above, landing on their human hosts. In water, leeches hang around in the sand and seaweed, attaching themselves to exposed skin as a person passes by.
While some studies have found bug repellents to effectively repel leeches, the best defense against leeches is to keep all skin covered. Tight socks are a great way to prevent water leeches, and long pants and sleeves help protect from land leeches. Leeches, though, can move from clothed areas to uncovered areas, and will often migrate from hands or ankles, up to the groin or torso. Often, the human host does not even realize that it has picked up a leech, because as they bite, leeches release an anesthetic, numbing the wound area. Generally, the leech wound is small, and while anti-coagulate properties in the leech saliva can make the wounds bleed a lot, they are not really dangerous or very painful.
Most leeches will gorge themselves on blood, then drop off on their own once they are full, taking anywhere from 20 minutes to many hours; one such feeding is enough to sustain a leech for weeks. Even though they are not very painful, and not usually dangerous, most people want to remove attached leeches. It is important that one not try to burn off a leech, or use salt or acids. Instead, you need to prompt the leech to release both its anterior and posterior suckers, then get rid of it. This needs to be done carefully, according to the following procedure.
Look at the leech, and identify the smaller, more tapered end; this is the anterior, or oral, sucker. The other end of the leech is the posterior, rear sucker. Carefully, but firmly, slide your finger towards the anterior end of the leech, then using your fingernail (or similar thin, flat object), push the sucker sideways, away from the skin. As you detach the suction, the leech should release its teeth; continue to push it gently until that end is completely dislodged. Then quickly detach the posterior sucker in the same fashion.
It is important to not pull at the leech, or use heat or chemicals that could traumatize the leech, as this could cause it to regurgitate into the wound, making it more subject to infection. Forcing the leech to detach through pulling can also cause the wound to tear, or for the leech to tear, leaving some of its jaw in the wound, increasing the chance for infection. While removing the leech, take great care not to let the leech reassert itself, as it will try to do. Once the leech is removed, discard it a safe distance away, then attend to the wound.
Leech wounds are not poisonous, but like any other cut or injury, particularly when incurred in a tropical or wet environment, it can quickly become infected. Thus, it is important to clean the wound carefully, and bandage it, keeping it free from dirt and contaminants. If a leech makes its way to a mucous membrane, or inside a body cavity, medical attention may be required to remove the leech.