The best way to avoid leeches while trekking is to keep them off your skin in the first place. Tuck your trousers into leech socks, treat socks and boot tops with a DEET repellent, and check your legs every 30 to 45 minutes on wet forest trails. If one does bite, slide a fingernail under its mouth to break the seal and flick it off. Do not pull it, burn it or pour salt on it.
Leech bites are unpleasant but rarely dangerous. This guide covers when and where leeches are worst in Nepal, which repellents work, the myths to ignore, safe removal, aftercare and a short gear checklist.
Quick answer: how to protect yourself from leeches
| Step | What to do | Why it works |
|---|---|---|
| Choose your season | Trek outside the monsoon (June to September), or pick a rain-shadow route | Land leeches need wet vegetation; they are scarce in the dry seasons |
| Cover up | Long trousers tucked into leech socks or long socks; gaiters | Leeches climb from the ground and look for gaps at the ankle |
| Use repellent | DEET on socks, boot tops, lower trousers and exposed skin | Field trials found DEET among the most effective leech repellents |
| Check often | Every 30 to 45 minutes in wet forest, and at every rest stop | A leech removed before it attaches cannot bite |
| Remove correctly | Fingernail or card under the oral (front) sucker, then flick off | Avoids tearing the skin and leaving the wound open longer |
| Clean and cover | Antiseptic, pressure, sterile plaster; change it as it soaks | Bleeding can last hours; keeping it clean prevents infection |
What are land leeches?
The leeches trekkers meet in Nepal are mostly land leeches, often of the genus Haemadipsa. They live on the ground and in low vegetation in damp forest, not in water. They are usually 1 to 3 cm long when hungry, brown or greenish, and as thin as a matchstick until they feed.
A leech has a sucker at each end. The smaller front (oral) sucker holds the jaws; the larger rear sucker is for gripping. Land leeches sense warmth, vibration and the carbon dioxide in your breath, and they move surprisingly fast by looping end to end towards a passing walker.
Once attached, a leech injects saliva containing an anaesthetic, so you often do not feel the bite, and an anticoagulant called hirudin, which stops your blood clotting. It drinks for 20 minutes or more, swells to several times its size, then drops off on its own.
When and where are leeches worst in Nepal?
Leeches are a monsoon problem. Nepal’s monsoon runs roughly from early June to late September, and in that period the wet, forested middle hills come alive with them. In the main trekking seasons of October to November and March to May you will rarely see one, though a few can appear in damp forest early in October or after heavy pre-monsoon storms in May. See our guide to the best season to travel in Nepal for month-by-month conditions.
Altitude
Most leech exposure in Nepal is between about 1,000 m and 3,000 m, with the densest populations usually below 2,500 m in thick forest. Above about 3,500 m, in the open high valleys of the Khumbu and Manang, leeches are rarely a problem even in the monsoon. In practice that means most bites happen in the first and last days of a trek, in the forested lower sections.
Leech risk by trekking region in the monsoon
| Region or trek | Monsoon leech risk | Where you will meet them |
|---|---|---|
| Annapurna south side: Poon Hill, Ghandruk, Annapurna Base Camp | High | Rhododendron and bamboo forest around Ghorepani, Chhomrong and the Modi Khola valley; one of Nepal’s wettest areas |
| Langtang | High below about 3,000 m | Forest between Syabrubesi and Lama Hotel; fewer higher up |
| Kanchenjunga and Makalu | Very high | Long stretches of low, wet forest in eastern Nepal |
| Manaslu Circuit and Tsum Valley | High on the lower Budhi Gandaki | Lower valley forest; much less above Samagaun |
| Everest region | Low to moderate | Forest around Lukla, Phakding and Monjo; rare above Namche Bazaar |
| Annapurna Circuit | Moderate low down, low higher up | Lower Marsyangdi valley; upper Manang lies in a rain shadow |
| Upper Mustang, Upper Dolpo, Nar Phu | Very low | Rain-shadow, semi-arid areas; good monsoon options |
Leeches are also common in lowland jungle such as Chitwan during the rains, so cover up on monsoon jungle walks too.
How to avoid leeches: prevention that works
1. Wear leech socks
Leech socks are tightly woven cotton or polyester over-socks that come up to the knee. You wear them over your normal hiking socks, tuck your trousers into them and tie them off below the knee. Leeches cannot bite through the dense weave, and the light colour makes them easy to see and flick off before they climb higher.
They are the single most effective piece of anti-leech kit and cost little (typically £8 to £20 a pair in the UK). You can also buy them cheaply in Kathmandu’s Thamel and in Pokhara trekking shops before the monsoon.
2. Close the gaps
- Wear long, lightweight trousers rather than shorts, tucked into your socks.
- Add gaiters to cover the boot-to-trouser gap.
- Wear boots or trail shoes, never sandals, on forest sections. See how to choose trekking shoes.
- Tuck your shirt in. Leeches that reach your waist will find the gap.
- Light-coloured clothing makes leeches easier to spot.
3. Use an effective repellent
DEET is the best-tested option. In Indian defence research trials against land leeches in Assam, DEET and the related compound DEPA gave the best protection when applied to cloth. Apply a 30 to 50% DEET product to your socks, boot tops, laces, lower trouser legs and any exposed skin, and reapply after river crossings or heavy rain.
A few notes:
- DEET can damage some plastics and synthetic fabrics, so test it on a small area of your gear first.
- Picaridin and permethrin-treated clothing are widely used against insects, but there is little published evidence on how well they deter leeches. Treat them as a supplement, not a replacement.
- In lab tests on Himalayan land leeches, cinnamon oil was the most effective of six essential oils tried. Timur oil, from the Nepali Sichuan pepper (Zanthoxylum armatum), performed about as well as one commercial repellent. Natural oils wear off faster than DEET.
4. Walk smart on the trail
- Keep to the centre of the path and avoid brushing through wet undergrowth and long grass.
- Do not sit or put your pack down on wet ground or logs; leeches will climb on to anything warm.
- The person at the front stirs leeches up. Walkers further back often collect more, so everyone should check.
- Keep moving through the worst stretches. Most bites happen when you stop.
- Check feet, ankles, legs and the backs of knees every 30 to 45 minutes, and check each other’s backs and necks.
5. At the teahouse
- Do a full body check when you arrive, including your scalp, waist and between your toes.
- Shake out boots, socks, clothes and your pack before bringing them inside.
- Keep your pack zipped and off the floor.
6. Drink only treated water
This is the one leech risk that is genuinely medical. Small aquatic leeches, including Dinobdella ferox, can enter the nose or throat when people drink from or wash in streams, springs and ponds. Doctors in Nepal and India regularly report nasal leech infestation, which usually shows up as repeated nosebleeds on one side, a blocked nose or a feeling of something moving.
Never drink straight from a stream. Treat all water with purification tablets, a filter or a UV purifier, and do not splash untreated water on your face. If you have unexplained one-sided nosebleeds after a trek, tell a doctor you have been in leech country.
Leech myths: salt, tobacco, soap and fire
| Method | Does it work? | Verdict |
|---|---|---|
| Salt on an attached leech | It makes the leech let go, but often only after it writhes and may regurgitate gut contents into the wound | Do not use for removal |
| Salt on socks and boots | Traditional deterrent; can discourage leeches from climbing | Acceptable as an extra, but it stings in cuts and damages leather |
| Tobacco water or tobacco-soaked socks | Nicotine is toxic to leeches and this is a long-standing practice in Asia | May help as a deterrent; avoid on broken skin, and nicotine is absorbed through the skin |
| Soap rubbed on socks | Some trekkers swear by it; little evidence | Harmless, but use DEET as well |
| Burning with a lighter or cigarette | Makes the leech drop off but risks burns and regurgitation | Do not use |
| Pulling it off | The jaws can tear the skin and the leech just reattaches to your fingers | Do not use |
| Insect repellent squirted on an attached leech | May cause regurgitation and irritates the wound | Use repellent to prevent, not to remove |
The concern with salt, heat and chemicals on an attached leech is that an irritated leech may vomit its blood meal, along with any bacteria, back into the bite. Doctor-reviewed medical guidance lists salting, burning, shampoo, insect repellent and pulling as methods to avoid for removal.
How to remove a leech safely
If a leech has attached, stay calm. It is not painful and you have time to do this properly.
- Find the front end. The narrow end with the small sucker is the mouth. It is usually the end attached to your skin, often with the fatter rear end also gripping.
- Pull the skin tight next to the leech with one hand.
- Slide a fingernail, a thin card or the edge of a credit card along your skin and under the front sucker to break the seal.
- Do the same to the rear sucker if it is still holding on.
- Flick it away straight away. A loose leech will try to reattach to your fingers.
- If you cannot remove it, or it is in your nose, mouth, ear or eye, it will drop off by itself once full, usually within about half an hour. Leeches inside the nose or mouth need a doctor.
Aftercare: what to do after a leech bite
A leech bite leaves a small Y-shaped or circular wound. Because of the anticoagulant in leech saliva, it can bleed freely for several hours, which looks alarming but is normal.
- Wash the bite with clean, treated water and soap, or an antiseptic wipe.
- Apply an antiseptic such as povidone-iodine or chlorhexidine.
- Press firmly with gauze for several minutes.
- Cover with a sterile plaster or dressing and change it as it soaks through.
- Do not scratch. Itching can last several days; a cold compress, a mild steroid cream or an oral antihistamine can help.
- Keep the wound clean and dry for the rest of the trek and check it each evening.
Signs of infection
Leeches commonly carry Aeromonas bacteria in their gut, and any open wound on a trek can also pick up skin bacteria. See a doctor or health post if you notice:
- Spreading redness, warmth or swelling around the bite.
- Pus, a bad smell or increasing pain after a day or two.
- Red streaks spreading from the bite.
- Fever or feeling generally unwell.
When to get medical help urgently
- Signs of a severe allergic reaction: swelling of the face or lips, a widespread rash, dizziness or difficulty breathing. This is rare but needs emergency treatment.
- Bleeding that will not stop with firm pressure, especially if you take blood thinners.
- A leech in your nose, mouth, throat, ear or eye.
- Many bites on a child or on someone with a blood or immune disorder.
Health posts and the guide on your trek can help, and your travel insurance for trekking should cover medical treatment. Our safety tips for trekking in Nepal cover first aid and evacuation more broadly.
Are leech bites dangerous?
For almost everyone, no. Land leeches are not known to be a significant route for disease transmission to people, and the blood loss from a few bites is small. The real risks are a bite becoming infected because it was scratched or not kept clean, a rare allergic reaction, and the nasal leeches described above. Leeches are mostly a nuisance that can be managed with the right kit and habits.
Anti-leech gear checklist
Add these to your usual trekking packing checklist if you are walking in the monsoon or in wet forest:
- Leech socks (two pairs, so one can dry)
- Lightweight long trousers, ideally quick-drying
- Gaiters
- Trekking boots or trail shoes with good grip
- DEET repellent, 30 to 50%
- Antiseptic wipes and povidone-iodine or chlorhexidine
- Sterile gauze and plasters
- Antihistamine tablets and anti-itch cream
- Water purification tablets, a filter or a UV purifier
- A thin card (an old loyalty card works) for removing leeches
- A dry bag or zipped pack cover
- Waterproof jacket and pack cover for monsoon rain
Should leeches put you off trekking in the monsoon?
Not necessarily, but they are one of several reasons the main trekking seasons are more popular. Monsoon treks also bring rain, cloud-hidden views, landslides and flight delays. If you want to trek between June and September, rain-shadow areas such as Upper Mustang or the upper Annapurna Circuit are far drier. If you choose a forested route such as Poon Hill or Langtang in the monsoon, go prepared and leeches become a minor part of the trip. New to trekking? Start with our beginner’s guide to trekking.
Frequently asked questions
How do you keep leeches off you when hiking?
Wear leech socks or long socks with your trousers tucked in, add gaiters, and treat socks and boot tops with a DEET repellent. Stay in the middle of the trail, avoid sitting on wet ground and check your legs every 30 to 45 minutes in wet forest.
Does salt kill leeches?
Salt will make a leech let go and can kill it, but you should not use it on an attached leech. It may make the leech regurgitate into the wound, which raises the risk of infection. Use a fingernail or card to break the seal instead.
Does DEET repel leeches?
Yes. Field trials against land leeches found DEET among the most effective repellents tested, particularly when applied to socks and clothing. Reapply after rain or river crossings.
Do leech socks really work?
Yes. Their tight weave stops leeches biting through, and tucking your trousers into them closes the ankle gap where most leeches get in. They are the most effective single item for monsoon trekking.
Why won’t a leech bite stop bleeding?
Leech saliva contains hirudin, an anticoagulant that stops blood clotting. A bite can bleed for several hours. Apply firm pressure and a sterile dressing, and get help if it will not stop or you take blood thinners.
Are there leeches on the Everest Base Camp trek?
Only a few, and mainly in the monsoon in the forested sections near Lukla, Phakding and Monjo. Above Namche Bazaar leeches are rare. In the main seasons of spring and autumn you are unlikely to see any.
When is leech season in Nepal?
Leech season matches the monsoon, roughly June to September. Numbers are highest in July and August in wet forest between about 1,000 m and 3,000 m. A few may linger into early October.
Can a leech get inside your body?
Land leeches bite the skin and drop off. Small water leeches can enter the nose or mouth if you drink from or wash in untreated streams and ponds, which is why you should treat all drinking water. A leech in the nose or throat needs a doctor.
