High-Altitude Travel: How to Prepare and Stay Healthy

Visiting high-altitude destinations can be an unforgettable experience—whether it’s trekking through the Andes, visiting the Himalayas, or exploring mountain towns like Cusco or La Paz. But traveling to elevations above 8,000 feet brings unique challenges for the body. Reduced oxygen levels at high altitudes can trigger symptoms ranging from mild fatigue to serious illness if you’re unprepared.

Understanding how altitude affects your body and how to properly prepare can help you stay safe and enjoy your trip to the fullest. This guide outlines essential steps to take before, during, and after your ascent into thinner air.

What happens to your body at high altitude

As you climb to higher elevations, the air becomes thinner—meaning there’s less oxygen in every breath. Your body responds by working harder to deliver oxygen to your organs and muscles. Most travelers begin to feel these effects at around 8,000 feet (2,400 meters) and above.

Common symptoms include:

Shortness of breath
Headache
Fatigue
Dizziness
Nausea or loss of appetite
Difficulty sleeping

These are signs of acute mountain sickness (AMS), the most common altitude-related condition. While many cases are mild and improve with rest, AMS can progress to more serious issues like high-altitude pulmonary edema (HAPE) or cerebral edema (HACE) if ignored.

Know your destination’s elevation

One of the first steps in planning high-altitude travel is researching your exact destination. Not all mountain locations are equally risky. For example:

Machu Picchu: ~7,970 ft
Cusco, Peru: ~11,200 ft
La Paz, Bolivia: ~11,900 ft
Lhasa, Tibet: ~11,500 ft
Mount Kilimanjaro Base: ~7,500 ft (summit ~19,300 ft)

If your itinerary includes rapid ascents or starts at elevations above 10,000 feet, the risk for altitude sickness is higher.

Schedule a pre-travel health check

A travel physical before departure helps assess whether you’re physically fit for high-altitude conditions. Your provider will consider:

Chronic conditions (asthma, heart disease, anemia)
Current medications and potential interactions
Past experience with high elevation
Options for preventive treatment (e.g., acetazolamide)

If you’re planning strenuous activity at elevation, like hiking or skiing, this visit is especially important.

Consider altitude sickness prevention medication

For travelers ascending quickly or visiting elevations above 10,000 feet, your provider may prescribe acetazolamide, a medication that helps the body adjust to altitude more efficiently. It works by acidifying the blood slightly, stimulating deeper and faster breathing.

Key points:

Start 1–2 days before ascent and continue during elevation gain
Helps reduce severity and duration of AMS symptoms
Not suitable for everyone—discuss side effects with your provider

Some may also use ibuprofen to help relieve symptoms like headache or inflammation associated with mild AMS.

Hydration and diet matter

Staying well-hydrated is critical at altitude. Dehydration makes symptoms worse and delays acclimatization. Drinking plenty of water (more than you might usually) and limiting alcohol and caffeine can help your body adjust.

Other tips:

Eat a light, high-carb diet for easier digestion and energy
Avoid heavy meals and alcohol during the first 24–48 hours
Snack frequently to maintain blood sugar and energy

You may lose your appetite at high altitudes, so small, frequent meals are a smart strategy.

Plan your ascent gradually

The best way to avoid altitude illness is to ascend slowly, giving your body time to acclimate. If possible:

Spend a night or two at a moderate elevation before climbing higher
Avoid flying directly into high-altitude cities without a day of adjustment
Limit physical activity for the first 24 hours at altitude
Follow the “climb high, sleep low” principle when trekking

Gradual ascent allows your body to make internal adjustments and increases your oxygen efficiency.

Recognize early symptoms and rest

Ignoring early signs of altitude sickness is one of the most common and dangerous mistakes. If you feel unwell, slow down and rest. The best treatment for mild AMS is to stop ascending and allow time for recovery.

Symptoms to monitor:

Persistent headache
Nausea or vomiting
Dizziness or coordination issues
Unusual fatigue or confusion

If symptoms worsen, descend immediately and seek medical attention. Waiting too long increases the risk of serious complications.

Essential items to pack for high-altitude trips

Your gear can help you adapt and respond to high-elevation travel. Include:

Acetazolamide (if prescribed)
Rehydration tablets or electrolyte drinks
Sunscreen and lip balm (UV is stronger at elevation)
Moisturizer for dry air
Pulse oximeter (to monitor blood oxygen saturation)
Light snacks and carbohydrate-rich foods
Layers for warmth (temperatures drop quickly)

Even non-strenuous activities can feel more taxing at altitude, so pack accordingly.

Adjust your physical activity expectations

Don’t expect to maintain your usual fitness level right away. Even light walking can feel exhausting in thinner air. Allow your body to adapt before attempting hikes, climbs, or intense exercise.

Tips include:

Take breaks frequently and rest as needed
Avoid overexertion in the first 48 hours
Listen to your body and go at a slower pace than usual

Being patient with your energy level will help your body adjust safely.

Takeaway

High-altitude travel can be rewarding, but it comes with real physiological stress. Preparing with the right knowledge, medications, and habits can help your body adjust and avoid serious illness. Whether you’re exploring mountain towns or summiting peaks, staying informed and cautious allows you to enjoy the view without risking your health.