Leeches in Vietnam: How to Remove One and Keep Them Off

Slide a fingernail under the narrow end of the leech, the end doing the biting, and push sideways until it lets go. Then do the same at the wide end and flick it away. Do not use salt, do not use a lighter, and do not pull. All three make a small clean bite into a wound that can get infected.

That is the whole of it. The rest of this is why those three shortcuts are worse than doing nothing, what actually stops leeches reaching your skin, and which weeks of the year you are likely to meet one at all.

The land leeches you meet in Vietnam

The leeches in Vietnamese jungle are land leeches, family Haemadipsidae, and the Vietnamese word you will hear guides use is con vắt. They live in leaf litter and on low vegetation, they find you by vibration, heat and shadow, and they move by looping end over end at a speed that is genuinely unsettling the first time you watch one cross a boot.

Two species turn up most often on treks in this part of Southeast Asia. Haemadipsa zeylanica is the plain brown one, common across the region's rainforest. Haemadipsa picta is the tiger leech, greenish brown on top with a yellow stripe down each side and an orange underside. The tiger leech tends to sit higher on vegetation and go for the arms and neck rather than the ankles, which is why the standard advice to tuck your trousers into your socks only solves half the problem.

They take a few millilitres of blood and drop off on their own in twenty minutes or so if you leave them alone. The bite itself is painless. Most people only notice when they see the blood.

The land leeches in Vietnamese forest are Haemadipsa, the same genus found across South and Southeast Asia. They are 2 to 4 centimetres at rest, they find you by heat and movement rather than smell, and they climb rather than drop out of trees, which is the first thing most guides have to talk people out of believing.

Why salt and fire are the wrong way to remove a leech

A leech attached to you has its gut full of bacteria and, in the wet season, a stomach that may still hold blood from something else in the forest. Anything that shocks it makes it empty that gut into the hole it has just made in you.

Salt does exactly that. The leech contracts violently and regurgitates before it releases, which is why parasitologists have spent years trying to get the salt advice retired. A flame works the same way, and leaves you with a burn on top of the bite. Pulling a leech off by force tends to tear the mouthparts, and those stay behind under your skin.

Wet leaf litter beside slow water is where you meet them, not in the trees.

This stopped being a theoretical point in 2026. A study in Transactions of the Royal Society of Tropical Medicine and Hygiene screened land leeches for viruses and found four new ones, three of them related to viruses that matter in animals and humans. The authors' concern was specifically mechanical transmission triggered by the way people remove leeches. The removal technique is the risk, not the leech.

Guides check the group at every rest stop, and they spot them faster than you will.

The fingernail method avoids all of it. Pull the skin taut so the leech cannot get purchase, slide a nail flat against your skin under the small sucker, and break the seal. The leech will try to reattach to your finger, which is harmless and which everyone finds revolting. Flick it into the undergrowth rather than crushing it.

Then expect it to bleed for a while

Leech saliva contains an anticoagulant, which is the point of the whole arrangement from the leech's side. The bite keeps seeping for an hour and sometimes for several, long after the leech has gone. This alarms people far more than it should.

Clean it with soap and water, put antiseptic on it, and cover it if the blood is going to annoy you. Do not bandage it tightly to stop the bleeding, because it will not work and you will only notice it more. Itching for a few days afterwards is normal. Spreading redness, heat or pus is not, and that is when you want a pharmacy.

The bleeding is hirudin, the anticoagulant in leech saliva, and it is why a bite that took 20 seconds can weep for half an hour after the leech has gone. It is also why the wound looks far worse than it is.

What keeps leeches off you

Repellent on fabric works considerably better than repellent on skin, because skin sweats and fabric holds the dose. The field numbers are good.

One number worth knowing if you are treating gear before a longer trip: DEET applied to fabric at 0.93 mg per square centimetre stayed effective for close to twenty days in testing. You treat the socks once at the start of a week in the jungle and you are done.

The combination that works in practice is unglamorous. Long trousers, tucked in, over treated socks, with boots that cover the ankle. Check your legs whenever the group stops. On longer adventure treks in Vietnam the guides do a check at every rest, and they are faster at spotting one on your back than you will ever be.

Socks over the trousers, then repellent on the socks. That order matters.

When leeches are worst in Phong Nha

Leeches need moisture. They are barely present in the dry months and they are everywhere in the days immediately after heavy rain, which in Phong Nha means roughly September through to December. The Vietnam rainy season runs differently in the centre of the country than it does in the north, and central Vietnam's wettest stretch is exactly when leech activity peaks.

Nothing lives on a cave floor for a leech to feed on.

Most encounters happen on the forest floor rather than in the caves. Inside a cave there is nothing for them to live on. The walk in is where you collect them, particularly on the damp shaded sections and anywhere the trail runs through thick leaf litter.

Wet trekking clothes and dry camp clothes, and never the same set. A leech on a wet sleeve is a nuisance; one in a dry sleeping bag is a bad night.

Dry-season treks between February and May are close to leech free. If the thought genuinely bothers you, that is the answer, and it is worth reading the best time to visit Vietnam before you fix your dates rather than after.

For scale: Quang Binh runs its rainy season from roughly mid-September to mid-December, and those 13 weeks are when the leaf litter stays wet enough for land leeches to be active on the forest floor all day rather than at dawn and dusk. From January to August they are present but sparse, and on the drier routes you can walk a whole day and see none. A 10 to 20 litre dry bag, long socks and DEET is the whole of the defence, and the operator supplies the boots, gloves and gaiters.

Where this matters in Phong Nha

Exposure tracks time under canopy, so it varies a lot between trips. The Tu Lan cave tours and the multi-day routes are where you are most likely to pick one up.

Two treks are closed in the wet months anyway, so they do not appear above: Bach Ma Discovery and the Do Quyen Waterfall trips are closed through September, October and November, and reopen on 1 December.

The show caves do not. If your plan is Paradise Cave and a boat into Phong Nha Cave, leeches are not part of your trip in any month. The boardwalks and the buggy road do not pass through the habitat.

Guides carry repellent and a first aid kit, and they treat leech removal as routine, which it is. Nobody on a Jungle Boss trek is expected to deal with one alone, and the honest position is that the leeches are a detail people remember fondly afterwards rather than a reason to change your plans. The rest of what to bring is in the jungle trek packing list, and how it fits a wider trip is in the Phong Nha itinerary.