Managing diabetes at altitude requires careful planning, but thousands of diabetic trekkers complete routes in Nepal every year. Understanding how altitude and exertion affect blood sugar is the key to staying safe. Learn more about diabetes and high-altitude trekking before you go.

How Altitude Affects Blood Sugar

At elevations above 3,500 m, your body undergoes significant physiological stress. These changes have a direct impact on glucose metabolism:

• Increased physical exertion during ascent can rapidly deplete glucose reserves, causing hypoglycaemia (low blood sugar) — sometimes faster than you expect.
• Altitude-induced anorexia (loss of appetite) makes it easy to under-fuel, amplifying hypoglycaemia risk.
• Cold temperatures and reduced oxygen can slow the absorption of subcutaneous insulin, causing delayed peaks.
• Altitude sickness itself can mask hypoglycaemia symptoms such as headache, confusion, and fatigue — the two conditions look identical.
• Dehydration (common at altitude) concentrates blood glucose, potentially pushing readings higher.

Insulin Storage in Cold Conditions

Nepal’s trekking seasons bring cold nights, especially above 4,000 m. Insulin can freeze, which renders it permanently ineffective:

• Never let insulin freeze. Store vials or pens close to your body during the day (inside jacket pockets).
• At night, keep insulin in an insulated pouch or sleep with it inside your sleeping bag.
• Carry a thermos or chemical hand-warmer in your pack for added insurance.
• Bring 2–3x your calculated insulin supply — altitude, activity, and illness can all alter requirements dramatically.
• Pre-filled insulin pens are more convenient than vials in the field; confirm your pen model works at altitude.

Signs to Watch For

Before You Go: What to Discuss with Your Doctor

• Request a pre-travel diabetes review — ideally 6–8 weeks before departure.
• Ask about adjusting basal insulin doses during sustained aerobic activity.
• Request a glucagon emergency kit and ensure your guide knows how to use it.
• Discuss CGM (Continuous Glucose Monitor) suitability — accuracy can decline at altitude.
• Get a letter confirming your medical need for insulin and syringes for customs.
• Ask your doctor’s guidance on altitude sickness medication (Diamox) — it can affect blood glucose.

What to Tell Your Guide

• Tell them you have diabetes on Day 1 — do not wait for an emergency.
• Show them where your glucose meter, fast-acting sugar (glucose tablets, juice), and glucagon kit are kept.
• Agree on a simple “low sugar signal” you can use if you’re unable to speak clearly.
• Inform them that “I’m feeling confused” is a medical symptom, not just altitude fatigue.

When to Stop Trekking

Asthma and altitude can be a tricky combination, but many asthmatic trekkers successfully complete routes in Nepal. Understanding how thin, cold air affects your airways is essential. Read the Asthma + Altitude primer from Asthma UK before planning.

How Altitude Affects the Airways

• Above 3,000 m, air pressure drops, meaning each breath delivers less oxygen. Your breathing rate increases, stressing already reactive airways.
• Cold, dry air at altitude is a major trigger for exercise-induced bronchoconstriction (EIB). The air at 5,000 m is dramatically drier than at sea level.
• Dust on dry-season trails can provoke attacks. Trekking in spring or autumn reduces but doesn’t eliminate this risk.
• Surprisingly, some asthmatics report fewer allergy-triggered symptoms at altitude due to reduced pollen and pollution. However, this is not universal.
• Altitude sickness and asthma attacks share symptoms (breathlessness, chest tightness) — making it difficult to distinguish one from the other without careful assessment.

Using Your Inhaler at Altitude

Your inhaler remains your most important tool, but cold weather and altitude change how it behaves:

• Keep your reliever inhaler (salbutamol/albuterol) in a warm pocket, not a cold bag. Cold reduces aerosol output from MDIs.
• A spacer becomes even more valuable at altitude, improving drug delivery when breathing is laboured.
• Consider asking your doctor about a dry-powder inhaler (DPI) as a backup — these are less affected by cold than MDIs.
• Preventive use of a reliever inhaler 15–20 minutes before strenuous uphill sections is often recommended for EIB sufferers.
• Bring at least double your normal inhaler supply. Resupply in remote trekking areas is not possible.

Which Treks to Approach with Caution

Not all Nepal treks are equal in terms of altitude and exertion. Asthmatics should be especially cautious about:

Better-suited alternatives for moderate asthmatics include the Ghorepani Poon Hill circuit (3,210 m max) and the lower Langtang Valley approach. A specialist trekking company like

Nepal Treks and Tour can customise these routes to keep your maximum altitude within a safer range.

Before You Go: What to Discuss with Your Doctor

• Get a formal
• asthma action plan updated for high-altitude trekking.
• Ask whether a short course of oral corticosteroids to treat a severe attack is appropriate for you to carry.
• Discuss whether acetazolamide (Diamox) for altitude sickness might interact with your asthma medications.
• Request spirometry testing to confirm your current lung function before travel.
• Consider a high-altitude altitude simulation test at a specialist clinic if your asthma is moderate-severe.

What to Tell Your Guide

• Show your guide your inhaler and spacer and explain what an asthma attack looks and sounds like.
• Tell them the difference between a mild attack (manageable with inhaler) and an emergency.
• Ensure they know the helicopter evacuation procedure — in remote Nepal, this is the primary emergency option.

When to Stop Trekking

Knee problems are the most common musculoskeletal complaint on Nepal treks. With the right preparation, technique, and route choice, they’re also the most manageable. See what physiotherapists recommend for trekking knee care.

The Real Problem: Descents

On trails like the descent from Thorong La or from Ghorepani, the damage isn’t done going up — it’s done going down. Here’s why:

• Descending steep trails places 3–5x your body weight through the knee joint per step.
• Patellofemoral pain syndrome (“trekker’s knee”) is the most common condition: aching around and behind the kneecap, typically worsened on downhills.
• Iliotibial (IT) band syndrome causes sharp lateral knee pain on descents, often appearing on Day 3–4 when muscles fatigue.
• Pre-existing osteoarthritis or cartilage damage means the cartilage “cushion” degrades faster under load.
• Tired legs in the afternoon cause poor technique, dramatically increasing injury risk. Many hikers sustain their worst knee damage in the last 30 minutes of a descent.

Trekking Pole Technique: Your Most Important Tool

Poles used correctly can reduce the load on each knee by up to 25%. Learn proper trekking pole technique before you leave home:

• Use two poles, not one. Asymmetric loading creates its own problems.
• On descents: extend poles 5–10 cm longer than uphill length. Plant the pole ahead of you and use it to brake your weight before your foot takes impact.
• Step placement: land with a slightly bent knee (never locked), and place your whole foot flat rather than heel-striking.
• Lean forward slightly on descents — leaning back loads the knee more.
• Take shorter steps on very steep sections. Switchback across the trail rather than straight down.
• Trekking poles with anti-shock mechanisms (internal spring) are worth the extra cost for knee sufferers.

Knee-Friendly Trek Recommendations

Before You Go: What to Discuss with Your Doctor

• Get a physiotherapy assessment focusing on quad and hip strengthening — start at least 8–12 weeks before your trek.
• Ask about knee bracing (patellar tracking braces vs. full sleeve braces) for your specific condition.
• Discuss NSAIDs (ibuprofen/naproxen) for trail use — they’re useful but have risks at altitude (dehydration, GI side effects).
• Ask about kinesiology taping (KT Tape) as a supplement to bracing.
• Consider a corticosteroid injection 3–6 weeks before departure if you have significant osteoarthritis.

What to Tell Your Guide

• Ask for a slower pace on all descents — this is a medical request, not a preference.
• Request stops to rest the knees every 45–60 minutes on long descent sections.
• Tell your guide which side is worse, so they can position themselves on the correct side for assistance if needed.
• Ask the guide to flag any alternative flat or gentle-descent trail options in advance.

When to Stop Trekking

The single most important thing you can do for a safe trek with a chronic condition is to work with an experienced local operator who understands medical limitations. Nepal Treks and Tour (NTT) specialises in customising itineraries for trekkers with health considerations.

How NTT Can Help

• Route modification: NTT can design custom itineraries that cap your daily altitude gain, avoid extreme descent sections, and build in acclimatisation days.
• Medical briefing for guides: NTT guides can be briefed on your specific conditions, warning signs, and emergency protocols before departure.
• Flexible itinerary: If you need to descend early, NTT can arrange alternative transport, helicopter bookings, or modified routing without losing the entire trek.
• Equipment support: Trekking poles, knee braces, and altitude medicine can be sourced in Kathmandu. NTT can advise on reputable gear suppliers in Thamel.
• Emergency contacts: NTT maintains relationships with helicopter evacuation companies and altitude medicine clinics.

Contact NTT directly to discuss your medical needs before booking: www.nepaltrekkingandtour.com. Their team includes guides with Wilderness First Responder training.

Get Travel Insurance That Covers Helicopter Evacuation

This is non-negotiable. Standard travel insurance often excludes high-altitude trekking or pre-existing conditions. Specialist providers like World Nomads or Global Rescue offer policies covering evacuation from high-altitude Nepal.

Carry Your Medical Summary in Nepali

Have your condition, medications, and emergency instructions translated into Nepali. Resources like the CIWEC Hospital travel medicine clinic in Kathmandu can assist with pre-trek medical consultations and documentation.

The ‘Ascend Slowly’ Rule Is Non-Negotiable

• Limit ascent to 300–500 m of sleeping altitude per day above 3,000 m.
• Build in at least one rest day for every 1,000 m of elevation gained.
• Never ascend to sleep at a higher altitude if you have symptoms of AMS (headache, nausea, fatigue, dizziness).