Travel Health Guide: Nepal
Planning a trip to Nepal? Get physician-reviewed advice on altitude sickness, malaria, vaccines, and traveler's diarrhea. Know exactly what meds you need before you go.
Travel Health Guide: Nepal
Nepal is one of the most medically demanding destinations for US travelers — not because of infectious disease alone, but because no other country combines high-altitude trekking, rural lowlands with active malaria transmission, and a capital city with persistent gastrointestinal risk all in a single trip. As a physician, I want you walking into Nepal prepared, not scrambling in a Kathmandu pharmacy. Here is exactly what you need: Diamox (acetazolamide) for anyone trekking above 3,000 meters, a traveler's diarrhea antibiotic standby for all travelers, and malaria prophylaxis if your itinerary includes the Terai lowlands (Chitwan, Lumbini, or the border region). Add hepatitis A and typhoid vaccines if you haven't had them recently. Altitude sickness strikes an estimated 50 percent of trekkers who ascend rapidly above 3,500 meters, and the Annapurna and Everest regions sit well above that threshold. Get your medications sorted before you leave — not after you arrive at 14,000 feet with a splitting headache.
Quick Facts
The Elevation Factor: Why Nepal Is Different
Most travel health conversations focus on infectious diseases. For Nepal, altitude is the dominant risk — especially for the hundreds of thousands of US travelers who visit each year specifically to trek the Himalayas.
Kathmandu sits at 1,400 meters (4,593 feet), which is not high enough to cause altitude sickness on its own. However, most popular trekking routes involve rapid ascents that push travelers well above the danger threshold. Lukla, the gateway village for Everest Base Camp treks, sits at 2,860 meters (9,383 feet). The Thorong La Pass on the Annapurna Circuit reaches 5,416 meters (17,769 feet). Everest Base Camp itself is at 5,364 meters (17,598 feet).
Acute mountain sickness (AMS) affects roughly 50 percent of trekkers who ascend to 3,500 meters (11,480 feet) quickly without adequate acclimatization. Symptoms include headache, fatigue, nausea, dizziness, and poor sleep. Without intervention, AMS can progress to high-altitude pulmonary edema (HAPE) or high-altitude cerebral edema (HACE), both of which are life-threatening emergencies requiring immediate descent and evacuation.
Acetazolamide (Diamox), taken at 125 mg twice daily starting one to two days before ascent, reduces AMS risk by approximately 48 percent compared to placebo, according to a Cochrane meta-analysis. If you are trekking above 3,000 meters, ask your physician about Diamox before your trip. Get Diamox delivered before your trek →
Altitude Sickness: What Trekkers Need to Know
Who Needs Diamox
Acetazolamide (brand name: Diamox) is the standard prescription medication for AMS prevention. The CDC recommends considering prophylaxis for travelers ascending to altitudes above 2,500 meters, particularly those with rapid ascent profiles.
A typical Everest Base Camp trek profile: fly from Kathmandu to Lukla (2,860m) on Day 1, reach Namche Bazaar (3,440m) by Day 2 or 3. Most commercial trek packages build in acclimatization days, but even well-structured itineraries cannot eliminate AMS risk entirely.
The standard prophylactic dose is 125 mg twice daily. Some guidelines recommend 250 mg twice daily for higher risk situations, but 125 mg is generally well-tolerated and effective for most trekkers. Start one to two days before your planned ascent above 2,500 meters and continue for at least 48 hours after reaching your highest planned altitude.
Common side effects of Diamox include tingling in the fingers and toes (paresthesias), increased urination, and altered taste of carbonated beverages. These are mild and expected, not signs of a problem. The medication works by stimulating your breathing, which helps your body compensate for lower oxygen levels at altitude.
Important: Diamox is a sulfa-containing medication. If you have a documented sulfonamide allergy, discuss alternatives with your physician. Dexamethasone is sometimes used as an alternative but carries different side effects.
Acclimatization Rules That Save Lives
Medication does not replace smart acclimatization. The "climb high, sleep low" principle means ascending during the day but descending to a lower elevation to sleep. The general guideline for treks above 3,000 meters: do not increase your sleeping altitude by more than 300 to 500 meters per day, and take a rest day every three to four days.
If you develop moderate to severe AMS symptoms — severe headache unresponsive to ibuprofen, confusion, inability to walk a straight line, or shortness of breath at rest — descend immediately. Do not sleep at that altitude. Helicopter evacuation is available from most Himalayan trekking routes, which is exactly why travel insurance with emergency evacuation coverage is non-negotiable for Nepal.
Traveler's Diarrhea: High Risk Across Nepal
Traveler's diarrhea (TD) is the most common illness among visitors to Nepal. The risk is high in Kathmandu and remains significant throughout trekking routes, where food preparation standards vary widely from lodge to lodge.
Enterotoxigenic E. coli (ETEC) is the most common bacterial culprit, but Nepal also has significant rates of Campylobacter (often quinolone-resistant), Shigella, and Giardia. Giardia lamblia is particularly prevalent in trekking areas due to contaminated water sources and is responsible for the classic "trekker's diarrhea" that develops days to weeks into a trip.
What to Pack
All travelers to Nepal should carry a standby antibiotic for self-treatment of moderate to severe TD. Two evidence-based options:
Azithromycin (1g single dose or 500mg daily for three days): Preferred for Nepal because of significant fluoroquinolone resistance in Campylobacter isolates, which is especially prevalent in South Asia. Azithromycin remains effective against most TD pathogens in this region.
Ciprofloxacin (500mg twice daily for three days): Still useful for some bacterial causes but has reduced efficacy against Campylobacter in Nepal specifically. If you have azithromycin, use it.
Tinidazole or metronidazole for Giardia: If diarrhea persists more than one to two weeks or you develop bloating, gas, and greasy stools consistent with Giardia, tinidazole (2g single dose) is first-line treatment.
Additionally, carry oral rehydration salts (ORS) and an antidiarrheal agent (loperamide/Imodium) for symptom control when you cannot stop trekking. Never use loperamide if you have fever or bloody diarrhea.
Get your traveler's diarrhea antibiotic before you go →
Water and Food Safety
Tap water is not safe in Nepal. Even in five-star Kathmandu hotels, drink only bottled water, water purified with iodine or chlorine tablets, or water boiled for at least one minute (three minutes above 3,500 meters, since water boils at a lower temperature at altitude). Many trekking lodges offer boiled water for a fee.
Stick to cooked foods, peel your own fruit, and avoid salads, uncooked vegetables, and raw dairy. Street food in Kathmandu is high risk. Dal bhat (lentil soup and rice) served hot from the kitchen is typically one of the safer options on trekking routes.
Malaria: Terai Only, Not Kathmandu
This is one of the most misunderstood aspects of Nepal travel health. Malaria does not occur in Kathmandu or in the trekking regions of the Himalayas. Malaria transmission is limited to the Terai — the flat southern lowland region bordering India — including areas around Chitwan National Park, Bardia National Park, and Lumbini (birthplace of the Buddha).
If your Nepal itinerary includes only Kathmandu, Pokhara, and trekking in the Annapurna or Everest regions, you do not need malaria prophylaxis.
If your itinerary includes an overnight stay in Chitwan, Bardia, or the Terai border region, prophylaxis is recommended. Both Plasmodium vivax and Plasmodium falciparum are present in the Terai. The CDC recommends atovaquone-proguanil (Malarone), doxycycline, or mefloquine for travelers to this zone.
Malarone is generally the most convenient option for short visits because it requires only one to two days of lead time before entering a malaria zone, compared to one to two weeks for mefloquine. Do I need malaria pills? →
Regardless of whether you take prophylaxis, use insect repellent (DEET 30 percent or higher) and sleep under permethrin-treated nets or in air-conditioned accommodations in the Terai region.
Vaccines for Nepal
Strongly Recommended for All Travelers
Hepatitis A: Nepal has one of the highest rates of hepatitis A transmission in South Asia. The virus spreads through contaminated food and water — exactly the exposure profile of every Nepal traveler. Two-dose series (0 and 6-12 months) provides lifetime protection. A single dose provides adequate protection for travel if given at least two weeks before departure.
Typhoid: High risk across Nepal, particularly for travelers spending time in Kathmandu or visiting rural areas. Two options: injectable Vi polysaccharide vaccine (one dose, valid for two years) or oral Ty21a live vaccine (four capsules over one week, valid for five years). Injectable is more convenient; oral provides slightly longer coverage.
Recommended for Some Travelers
Japanese Encephalitis (JE): JE virus is transmitted by Culex mosquitoes in rural agricultural areas. Transmission season peaks from May through October (monsoon season). The CDC recommends JE vaccine for travelers spending more than a month in rural Nepal, or for shorter trips during peak transmission season with significant outdoor exposure in rural areas. The Ixiaro two-dose series (given 28 days apart) provides reliable protection.
Rabies: Nepal has one of the highest rates of human rabies exposure in Asia, primarily from dog bites. The CDC recommends pre-exposure prophylaxis for travelers spending more than a month in Nepal, those with significant outdoor exposure (trekking, cycling), and travelers working with animals. Pre-exposure vaccination simplifies post-exposure management significantly — instead of needing rabies immune globulin (which may be unavailable in rural Nepal), you only need two booster vaccine doses.
Altitude destinations note: If you are trekking in remote areas where medical care is more than 24 hours away, rabies pre-exposure vaccination becomes more important — you will not be able to access appropriate post-exposure treatment easily.
Routine Vaccines to Verify
Before any international travel, confirm you are current on:
- MMR (measles-mumps-rubella): Confirmed outbreaks occur periodically in Nepal
- Tdap (tetanus-diphtheria-pertussis): Especially important for trekkers with wound exposure risk
- COVID-19: Keep your primary series and boosters current
- Influenza: Year-round transmission in Nepal, higher risk in group settings like trekking lodges
Book your Nepal vaccines online through Wandr →
Travel Insurance for Nepal: Not Optional
Nepal requires a special category of travel insurance that specifically includes emergency medical evacuation. Standard travel insurance policies often cap medical benefits at $50,000, which can be exceeded by a single helicopter evacuation from Everest Base Camp or Annapurna.
Look for a policy that includes:
- Emergency medical evacuation with no dollar cap (or a cap above $500,000)
- High-altitude trekking or adventure activities (many standard policies exclude this)
- Medical repatriation to your home country if needed
- 24/7 emergency assistance with Nepal coverage
World Nomads, Global Rescue, and similar adventure-focused travel insurance providers are well suited for Nepal. Himalayan Rescue Association membership cards are also worth considering for trekkers; they provide evacuation coordination services for a flat annual fee.
Nepal's terrain makes on-the-ground evacuation extremely slow. Helicopters are the primary medical evacuation vehicle from most high-altitude trekking routes. Insurance is not a luxury — it is the difference between an expensive inconvenience and a financially devastating emergency.
Health Tips for Trekking
Hydrate aggressively. Dehydration accelerates altitude sickness. Aim for three to four liters of water per day at altitude. Monitor your urine color — it should be pale yellow, not dark.
Watch for HAPE and HACE warning signs. If you hear crackling in your chest, feel severely short of breath even at rest, or develop confusion or loss of coordination at altitude, descend immediately and get to medical care. These are life-threatening emergencies.
Sun protection. UV radiation is significantly more intense at altitude. At 4,000 meters, UV exposure is approximately 40 percent higher than at sea level. SPF 50+, sunglasses with UV protection, and a wide-brimmed hat are not optional.
Frostbite awareness. Temperatures on high-altitude routes can drop to -20°C (-4°F) or below at night. Proper layering, insulated sleeping bags rated below -10°C, and waterproof outer layers are essential. Wet extremities freeze faster — keep your hands and feet dry.
Trek with a licensed guide. Beyond safety benefits, a knowledgeable guide will recognize AMS symptoms in your group and help enforce acclimatization rules. Solo trekking above 4,000 meters significantly increases mortality risk from altitude illness.
Nepal Health Packing Checklist
- Diamox (acetazolamide) — 125mg twice daily, prescribed by physician
- Standby antibiotic for TD (azithromycin preferred)
- Oral rehydration salts (ORS) — 10-12 packets
- Water purification tablets or SteriPen UV purifier
- Ibuprofen (headache, altitude symptom management)
- Loperamide (Imodium) for acute diarrhea symptom relief
- DEET insect repellent (30% or higher) — if visiting Terai
- Permethrin-treated clothing (if visiting Terai)
- High-SPF sunscreen (50+)
- Blister kit and moleskin
- Elastic bandage for sprains
- Personal prescription medications (with enough supply for delays)
- First aid kit with wound care supplies
- Emergency evacuation insurance card and 24/7 emergency number
- Copies of all prescriptions and physician contact information
About the Author
This guide was written by Dr. Alec Freling, the co-founder and medical director of Wandr. All clinical recommendations are based on current CDC Travel Health Notices, WHO International Travel and Health guidelines, and peer-reviewed medical literature.
Medical Disclaimer
This content is for informational purposes only and does not constitute medical advice. Every traveler's health situation is different. Consult a licensed physician before starting any prescription medication or vaccine series. For a personalized Nepal travel health consultation, visit travelwithwandr.com.
FAQ
Do I need malaria pills for Nepal? Only if you are visiting the Terai lowland region, which includes Chitwan National Park, Bardia National Park, and Lumbini. Malaria does not occur in Kathmandu or in the Himalayan trekking regions. Travelers going only to Kathmandu, Pokhara, and trekking routes do not need malaria prophylaxis.
What is the best medication for altitude sickness in Nepal? Acetazolamide (Diamox), taken at 125 mg twice daily starting one to two days before ascending above 2,500 meters, reduces acute mountain sickness risk by approximately 48 percent. It requires a prescription and should be started under physician guidance. Ibuprofen can help manage mild AMS headaches but does not prevent AMS.
What vaccines do I need for Nepal? Hepatitis A and typhoid are strongly recommended for all travelers to Nepal. Depending on your itinerary and length of stay, Japanese encephalitis and rabies pre-exposure vaccines may also be warranted. Ensure your routine vaccines (MMR, Tdap, COVID-19, influenza) are current before departure.
Is tap water safe to drink in Nepal? No. Tap water is not safe anywhere in Nepal, including Kathmandu. Drink only bottled water, boiled water (at least one minute at sea level, three minutes at altitude), or water treated with iodine tablets or a UV purifier. This applies even in high-end hotels.
How do I prevent traveler's diarrhea in Nepal? Carry a standby antibiotic (azithromycin is preferred due to high quinolone-resistant Campylobacter rates in Nepal), drink only safe water, eat only fully cooked foods, avoid raw vegetables and salads, and peel your own fruit. Oral rehydration salts are important to manage any diarrhea that does develop.
How serious is altitude sickness on the Everest Base Camp trek? Acute mountain sickness (AMS) affects roughly 50 percent of trekkers who ascend quickly above 3,500 meters. Most cases are mild and respond to rest, hydration, and ibuprofen. However, severe AMS can progress to high-altitude pulmonary edema (HAPE) or cerebral edema (HACE), which are life-threatening and require immediate descent and evacuation. Having Diamox on hand and knowing the warning signs is essential.
Do I need travel insurance for Nepal? Yes. Travel insurance with emergency medical evacuation coverage is essential for Nepal. Helicopter evacuations from trekking routes can cost $5,000 to $50,000 or more. Standard travel policies may exclude adventure activities and often have inadequate medical limits. Choose a policy specifically covering high-altitude trekking with no evacuation cap.
When is the best time to trek in Nepal for health reasons? October through November (post-monsoon) and March through May (pre-monsoon) are the primary trekking seasons. These windows offer the best trail conditions and visibility. Monsoon season (June through September) brings heavy rainfall, trail washouts, and elevated risk of gastrointestinal illness. Japanese encephalitis transmission peaks during the monsoon season.
Sources
- Centers for Disease Control and Prevention. "Nepal Destination Page." CDC Travel Health Notices. https://wwwnc.cdc.gov/travel/destinations/traveler/none/nepal
- Basnyat B, et al. "Acetazolamide for the prevention of acute mountain sickness: a systematic review and meta-analysis." BMJ. 2012;344:e1429.
- World Health Organization. "International Travel and Health: Nepal." WHO. https://www.who.int/ith/
- Pharmacist Letter. "Traveler's Diarrhea — Management and Treatment." 2025.
- Jensenius M, et al. "Infectious diseases in travelers to Nepal." Journal of Travel Medicine. 2012;19(5):279-285.
- Wilderness Medical Society. "Practice Guidelines for the Prevention and Treatment of Acute Altitude Illness." Wilderness & Environmental Medicine. 2019;30(4S):S3-S18.