What to Pack for High-Altitude Trekking (Health Edition)

Most high-altitude packing lists nail the boots and the down jacket and then quietly skip the part that actually decides how your trek goes: your altitude health plan. The single biggest reason people turn back on the way to Machu Picchu, the summit of Kilimanjaro, or Everest Base Camp is not cold or fitness. It is altitude illness, and the Wilderness Medical Society reports that acute mountain sickness affects roughly 25 percent of travelers who ascend above 8,000 feet (2,500 meters) and the majority of those who climb above 10,000 feet without a careful plan. So before you obsess over gear, sort five health essentials: a slow acclimatization schedule, acetazolamide (Diamox) discussed with a clinician before you leave, sun and UV protection for the thin air, a fingertip pulse oximeter, and a small kit for headaches, hydration, and traveler's diarrhea. Get those right and the boots, layers, and trekking poles are the easy part.

This is a complete, genuinely useful high-altitude trekking packing list, built so the gear sits alongside the medical prep instead of treating your health as an afterthought. It applies to the classic high-altitude routes: the Inca Trail and Cusco region in Peru, Kilimanjaro in Tanzania, the Everest Base Camp and Annapurna treks in Nepal, the Salkantay, and any itinerary that takes you past roughly 8,000 feet. Prefer to carry this with you? You can save or print this page as a checklist for your pack.

The five altitude health essentials to sort first

Everything else on this list is comfort and logistics. These five are what keep a trek from ending early in a clinic or a hasty descent.

1. An acclimatization plan. Altitude illness is a function of how fast you go up, not how fit you are. The CDC advises ascending no more than 1,600 feet (500 meters) of sleeping elevation per day above 8,000 feet, with a rest day every 3,000 to 3,300 feet. Marathoners get acute mountain sickness too. Plan the schedule before you book.
2. Acetazolamide (Diamox), if appropriate for you. This prescription medication speeds acclimatization and roughly halves the risk of acute mountain sickness, according to multiple Cochrane reviews. The standard CDC preventive dose is 125 mg twice daily, started 24 hours before ascent. It is not right for everyone, including people with a sulfonamide allergy, so this is a conversation to have with a clinician in advance.
3. Sun and UV protection. UV radiation rises about 10 to 12 percent for every 1,000 meters of elevation, and snow reflects up to 80 percent of it back at you. High-altitude sunburn and snow blindness are common and entirely preventable.
4. A fingertip pulse oximeter. A cheap, lightweight device that reads your blood oxygen saturation. It will not diagnose altitude illness on its own, but a trending drop paired with symptoms is a useful, objective signal that you and your guide should slow down or descend.
5. A symptom kit. Ibuprofen for altitude headache, oral rehydration salts, and a traveler's diarrhea plan, because stomach bugs are common on trekking routes and dehydration makes altitude worse.

We break each of these down below, then give you the full clothing, gear, and documents list.

The altitude health kit (the part other lists skip)

Pack this in a small, clearly labeled pouch you keep in your daypack, not buried in your duffel. On summit day or a long pass, you want it within arm's reach.

Prescription medications

• Acetazolamide (Diamox) for altitude sickness prevention and treatment. The preventive regimen most clinicians follow is 125 mg twice daily, beginning 24 hours before you start climbing and continuing for 2 to 3 days at your highest altitude. It works by acidifying the blood, which tricks your body into breathing faster and acclimatizing sooner. Expect tingling fingers and toes, more frequent urination, and flat-tasting carbonated drinks. These are normal, not dangerous.
• Dexamethasone, carried only on the advice of a clinician for higher or more committing routes. It treats moderate to severe altitude illness but does not help you acclimatize, so it is a rescue medication, not a daily one.
• Antimalarials if your trek combines altitude with a malaria-risk region. Kilimanjaro itself is above the mosquito line, but the days you spend in Moshi, Arusha, or on safari before and after are malaria territory. The same goes for the Peruvian Amazon if you add it to a Cusco trip. Check the CDC destination page for your specific route.
• A traveler's diarrhea antibiotic (such as azithromycin) prescribed in advance, plus loperamide for symptom control. Contaminated water and food are common on remote trekking circuits.
• Any personal daily prescriptions, in their original labeled containers, with enough supply for the whole trip plus several spare days in case of delays.

On Wandr, our clinicians review your route and medical history and, where appropriate, call your altitude prescription in to your local pharmacy for pickup before you fly. That removes the scramble of trying to find a travel clinic appointment in the weeks before departure.

Over-the-counter and first aid

• Ibuprofen or acetaminophen for altitude headache and sore muscles
• Oral rehydration salts (several packets; dehydration mimics and worsens altitude symptoms)
• Anti-nausea medication, since nausea is a core symptom of acute mountain sickness
• Throat lozenges for the dry, irritating "Khumbu cough" of cold high-altitude air
• Blister care: hydrocolloid plasters, moleskin, and athletic tape
• Antiseptic wipes, a small selection of bandages, and antibiotic ointment
• A broad-spectrum antihistamine
• Electrolyte tablets to add to your water

Monitoring and protection

• Fingertip pulse oximeter. At sea level, oxygen saturation reads 98 to 100 percent. By 12,000 to 14,000 feet, readings in the high 80s are common and not automatically alarming. What matters is the trend alongside how you feel.
• Sunscreen, SPF 30 or higher, applied to every exposed surface including under your nose and chin where reflected light hits.
• SPF lip balm, which people forget and regret.
• Category 4 (glacier-grade) sunglasses or goggles for snow and very high altitude, to prevent photokeratitis (snow blindness).

How to use the pulse oximeter without scaring yourself

A pulse oximeter is a tool, not a verdict. Clip it on, stay still, and take the reading after the number settles for several seconds. A one-time low number after you have just climbed hard means little. A saturation that keeps falling day over day, or a reading paired with a worsening headache, poor sleep, loss of appetite, or unsteadiness, is your cue to stop ascending and tell your guide. The cardinal rule of altitude, from the CDC and every wilderness medicine authority, is simple: if you have symptoms of altitude illness, do not go higher until they resolve, and if they get worse, go down. Descent of even 1,000 to 3,000 feet is the most reliable treatment there is.

Clothing: layer for a 50-degree daily swing

High-altitude trekking means big temperature swings, often from sweating in the sun at midday to well below freezing before dawn. The answer is layers you can add and shed quickly, not one heavy coat.

Base layers (next to skin):

• 2 to 3 moisture-wicking synthetic or merino wool tops
• 1 to 2 pairs of base-layer leggings for cold mornings and summit night
• Merino wool socks (3 to 4 pairs) plus liner socks to reduce blisters

Mid layers (insulation):

• 1 fleece or light insulated jacket
• 1 packable down or synthetic puffy jacket for camp and high passes

Outer layers (weather protection):

• Waterproof, breathable rain jacket and rain pants
• Trekking pants (convertible zip-off pants are versatile)

Extremities (where you lose the most heat):

• Warm hat or beanie that covers the ears
• Wide-brimmed sun hat or cap for daytime UV
• Lightweight liner gloves plus insulated waterproof gloves
• Buff or neck gaiter to warm cold, dry air before it hits your lungs

Footwear and trekking gear

• Broken-in waterproof hiking boots with ankle support. Never bring brand-new boots to altitude. Blisters at 14,000 feet end treks.
• Camp shoes or sandals to let your feet recover in the evening
• Trekking poles, which reduce knee load on descent by up to 25 percent according to gait studies and improve stability on scree and snow
• Gaiters for snow, mud, and scree
• Microspikes or crampons if your route crosses snow or ice (confirm with your operator)
• Headlamp with spare batteries, essential for the pre-dawn summit starts on Kilimanjaro and many passes
• Daypack (20 to 35 liters) with a rain cover for what you carry yourself
• Duffel or backpack for porter-carried or main luggage, within your operator's weight limit

Hydration and water treatment

Dehydration is one of the most common avoidable problems at altitude. You lose more water through faster breathing and dry air than you expect. Aim for 3 to 4 liters a day.

• Insulated water bottles or a hydration bladder (bladders can freeze on summit night, so carry at least one bottle as backup)
• A water treatment method: purification tablets, a UV purifier, or a filter rated for backcountry use
• A thermos for warm drinks, which double as a way to keep fluids from freezing

Documents, money, and the boring essentials

• Passport plus printed and digital copies stored separately
• Travel insurance documents, ideally a policy that explicitly covers high-altitude trekking and emergency evacuation (many standard policies exclude trekking above a set elevation, so read the fine print)
• Any required permits (the Inca Trail, for example, requires a permit booked months ahead through a licensed operator)
• Vaccination records, including a yellow fever certificate if your wider itinerary requires one
• Cash in small denominations for tips, local fees, and teahouses
• Phone, charger, power bank, and the right plug adapter

A realistic acclimatization timeline

Packing the right gear means nothing if you ascend too fast. Use this framework and let the schedule, not your ego, set the pace:

• Arrive a little low and sleep before climbing high. Spend a night or two at an intermediate elevation. Flying straight into Cusco at 11,150 feet and hiking the same day is a classic mistake.
• "Climb high, sleep low." It is fine to hike to a higher point during the day, as long as you come back down to sleep.
• Cap your sleeping ascent at about 1,600 feet (500 meters) per day above 8,000 feet, with a rest day every 3,000 to 3,300 feet.
• Start acetazolamide 24 hours before ascent if you and your clinician have decided it is right for you.
• Hydrate, ease off alcohol, and eat enough carbohydrates, which your body burns efficiently for fuel at altitude.

For a route-by-route breakdown, see our altitude hiking health guide and our day-by-day Kilimanjaro trek itinerary, both of which weave the acclimatization timeline into the plan.

Save hundreds compared to a travel clinic visit. Our clinicians can review your route and, where appropriate, send your altitude prescription to your local pharmacy for pickup before you fly. Get started with a pre-trip health check.

Quick high-altitude trekking packing checklist

Altitude health kit: acetazolamide (Diamox), pulse oximeter, ibuprofen, oral rehydration salts, anti-nausea medication, traveler's diarrhea plan, blister care, SPF 30+ sunscreen, SPF lip balm, glacier-grade sunglasses, personal prescriptions.

Clothing: base layers, fleece, down jacket, waterproof shell and pants, trekking pants, warm hat, sun hat, gloves, buff, merino socks.

Gear: broken-in boots, camp shoes, trekking poles, headlamp, daypack with rain cover, duffel, gaiters, microspikes if needed.

Hydration: insulated bottles, hydration bladder, water treatment, thermos.

Documents: passport and copies, trekking-specific travel insurance, permits, vaccination records, cash, electronics and adapters.

The bottom line

A high-altitude trek rewards the people who treat their health plan as core gear, not an afterthought. The clothing keeps you comfortable and the boots keep you moving, but it is the acclimatization schedule, the altitude medication conversation you have before you leave, and the small health kit in your daypack that decide whether you stand on the pass or turn around below it. Pack slow, ascend slower, and build the trip around the five essentials. The mountain is not going anywhere.

Trekking above 8,000 feet? Talk to a Wandr clinician about whether altitude sickness medication is right for your route, with a prescription called in to your local pharmacy for pickup. See altitude sickness options.

Frequently asked questions

What should I pack for altitude sickness on a trek? Build a small altitude health kit: acetazolamide (Diamox) if a clinician has prescribed it, a fingertip pulse oximeter, ibuprofen for headaches, oral rehydration salts, anti-nausea medication, and high-SPF sun protection including glacier-grade sunglasses. Keep it in your daypack, not your main luggage, so it is reachable on the trail.

Do I need Diamox for Machu Picchu or Kilimanjaro? Many trekkers benefit from it. Cusco sits at about 11,150 feet and Kilimanjaro's summit reaches 19,341 feet, both well into the zone where acute mountain sickness is common. Acetazolamide roughly halves the risk of altitude illness when started 24 hours before ascent, but it is not right for everyone. Discuss it with a clinician before your trip. See our guides on Diamox for Cusco and Machu Picchu and Diamox for Kilimanjaro.

How high is "high altitude" for trekking? Most authorities, including the CDC, define high altitude as 8,000 to 12,000 feet (2,500 to 3,700 meters), very high altitude as 12,000 to 18,000 feet, and extreme altitude above 18,000 feet. Acute mountain sickness becomes common above 8,000 feet, which is why acclimatization planning starts there.

Is a pulse oximeter worth packing? Yes, as one input among several. It gives you an objective oxygen saturation trend, which is useful when paired with how you feel. It does not replace symptom awareness, and a single low reading after hard climbing is not cause for panic. A saturation that keeps dropping alongside worsening symptoms is your signal to stop ascending or descend.

What is the most important thing to prevent altitude sickness? A slow ascent. Altitude illness is driven by how fast you climb, not your fitness level. Cap your sleeping elevation gain at about 1,600 feet per day above 8,000 feet, take rest days, hydrate, and avoid alcohol while acclimatizing.

Does travel insurance cover high-altitude trekking? Not always. Many standard policies exclude trekking above a set elevation or require a specific high-altitude add-on, and emergency helicopter evacuation from a remote trek can cost thousands. Read your policy's altitude limit and evacuation coverage carefully, and choose one that explicitly covers your route's maximum elevation.

Can I get my altitude medication online before I leave? Yes. Rather than chasing a travel clinic appointment, you can have a clinician review your route and medical history online and, where appropriate, send the prescription to your local pharmacy for pickup. See how to get altitude sickness medication online.

Sources

• Centers for Disease Control and Prevention. CDC Yellow Book, "High Elevation Travel and Altitude Illness." https://wwwnc.cdc.gov/travel/yellowbook/2024/environmental-hazards-risks/high-elevation-travel-and-altitude-illness
• Wilderness Medical Society. "Clinical Practice Guidelines for the Prevention and Treatment of Acute Altitude Illness." Wilderness & Environmental Medicine.
• Cochrane Database of Systematic Reviews. "Acetazolamide for the prevention of acute mountain sickness."
• World Health Organization. International travel and health guidance on altitude.
• World Meteorological Organization / WHO. Guidance on ultraviolet radiation and altitude.

Medical disclaimer: This article is for general educational purposes and is not a substitute for individualized medical advice. Altitude medications, including acetazolamide, are not appropriate for everyone. Talk to a licensed clinician about your specific route, health history, and medications before you travel.