Everything about altitude sickness and how to prevent it on your trek

Understanding Altitude

Cusco sits at 3,400 meters above sea level. Choquequirao at 3,050 meters. The mountain passes on our routes reach 4,650 meters. At these altitudes, the air contains less oxygen and the body needs time to adapt.

Altitudes on our tours:

What is Altitude Sickness (Soroche)

Altitude sickness occurs when the body does not have enough time to adapt to the reduced amount of oxygen in the air. It can affect anyone, regardless of their physical condition. Elite athletes suffer from it just as much as sedentary people.

Mild symptoms (very common):

• Headache
• Fatigue or unusual tiredness
• Mild dizziness
• Difficulty sleeping
• Loss of appetite
• Mild nausea
• Feeling short of breath when walking

Moderate symptoms (require attention):

• Intense headache that does not respond to painkillers
• Persistent nausea or vomiting
• Difficulty walking in a straight line
• Extreme fatigue
• Shortness of breath at rest

Severe symptoms (medical emergency):

• Mental confusion
• Severe difficulty breathing
• Cough with pink-tinged sputum
• Loss of coordination
• Blue-tinged lips or fingernails

Severe symptoms are rare but dangerous. They require immediate descent and medical attention. Our guides are trained to identify them and act accordingly.

Risk Factors

Factors that increase risk:

• Ascending too quickly (without acclimatization days)
• Not being well hydrated
• Consuming alcohol in the first days
• Doing intense exercise before acclimatizing
• Having suffered severe altitude sickness before
• Certain medical conditions (cardiac, respiratory)

Factors that do NOT affect risk:

• Age (young and old have the same risk)
• Sex (men and women equally)
• Physical fitness (athletes can suffer it just as much)
• Having been at altitude before (does not generate permanent immunity)

How to Acclimatize

Before the Trek

Arrive in Cusco with time to spare:

• Minimum 2 full nights before the trek
• Ideal: 3 nights for routes with passes above 4,000 m
• If you are coming from sea level, consider an intermediate night (Sacred Valley at 2,800 m)

First hours in Cusco:

• Do nothing strenuous
• Walk slowly
• Rest if you feel fatigue
• Do not run up the hotel stairs

First full day:

• Gentle walk around the city
• Visit nearby sites at the same altitude
• Do not do tours to higher places (such as Rainbow Mountain)
• Light meals
• No alcohol

Second day:

• You can gradually increase activity
• An excursion to the Sacred Valley (lower than Cusco) is a good option
• Continue staying hydrated

During the Trek

The trek to Choquequirao helps with acclimatization: on the first day you descend from 2,900 m to 1,900 m. On the second day you climb to 3,050 m. This gradual profile allows the body to adapt.

For routes with high passes:

• The ascent is progressive over several days
• We always sleep lower than the maximum point reached during the day
• Guides adjust the pace according to how the group is feeling

Golden rule: “Climb high, sleep low” — You can reach greater heights during the day, but always descend to sleep.

Prevention

Hydration The dry air at altitude dehydrates quickly. Dehydration worsens altitude sickness symptoms.

• Drink 3–4 liters of water per day
• Start hydrating well from the moment you arrive in Cusco
• Avoid diuretic drinks (coffee, alcohol) in the first days
• Urinate frequently (a sign of good hydration)
• Urine color should be clear, not dark

Nutrition

• Light, frequent meals
• Avoid heavy or fatty foods
• Complex carbohydrates for sustained energy
• Avoid alcohol completely in the first days
• Reduce salt intake

Preventive Medication

Acetazolamide (Diamox): The most effective medication for preventing altitude sickness. It accelerates acclimatization.

• Typical dose: 125–250 mg twice daily
• Start 24 hours before ascending to altitude
• Continue during the first days at altitude
• Requires a medical prescription
• Side effects: tingling in the hands and feet, increased urination, change in taste of carbonated drinks
• Consult a doctor before use

Ibuprofen: Studies show it helps prevent altitude headaches.

• 400–600 mg every 8 hours
• Start the day before ascending
• Do not use if you have stomach problems

Coca leaves: Traditional Andean remedy. Its effectiveness is not scientifically proven, but it is part of the local culture and many travelers report relief.

• Coca tea (mate de coca): available in all Cusco hotels
• Leaves for chewing: purchased at markets
• Coca sweets: easy to carry

Other Measures

• Avoid smoking (further reduces available oxygen)
• Do not take sleeping pills (they suppress breathing)
• Sleep slightly elevated (use an extra pillow)
• Do not ignore symptoms: tell the guide how you are feeling

What to Do If You Have Symptoms

Mild Symptoms

• Rest and reduce activity
• Drink more water
• Take painkillers (paracetamol or ibuprofen)
• Inform the guide
• Do not ascend further until they improve
• Generally pass within 12–24 hours

Moderate Symptoms

• Stop ascending
• Consider descending 300–500 meters
• Aggressive hydration
• Medication under the guide’s supervision
• Supplemental oxygen (our guides carry this)
• Constant monitoring

Severe Symptoms

• Immediate descent
• Supplemental oxygen
• Evacuation to a medical center
• Our guides have satellite communication and emergency protocols

Oxygen on Our Tours

All our tours include emergency oxygen. Guides carry:

• Portable oxygen cylinder
• Face mask
• Pulse oximeter to measure oxygen saturation

This is for emergencies, not for routine use. The goal is natural acclimatization, but we have backup if something goes wrong.

Altitude Profile by Tour

Classic Trek 4D/3N Day 1: 2,900 m → 1,900 m (descent) Day 2: 1,900 m → 3,050 m (ascent) Day 3: 3,050 m → 1,900 m (descent) Day 4: 1,900 m → 2,900 m (ascent)

Risk of altitude sickness: Moderate. The highest point is 3,050 m, similar to Cusco. Acclimatization in Cusco is sufficient.

Tours with the San Juan Pass Maximum point: 4,650 m Risk of altitude sickness: High on the day of the pass. You reach the pass after several days of trekking, which helps. But it is important to have acclimatized well in Cusco.

Inca Trilogy with Vilcabamba Range: 1,000 m (Espíritu Pampa) to 4,650 m (San Juan Pass) Variable risk. The trek rises and falls dramatically. Some days at altitude, others in low jungle. The variety helps but also challenges the body.

Frequently Asked Questions about Altitude

Can I do the trek if I have had altitude sickness before? Yes, but with extra precautions. Let us know your history. You may need more acclimatization days and preventive medication.

Is altitude sickness dangerous? Mild symptoms are very common and harmless. Severe symptoms are rare but require immediate attention. That is why our guides are trained and carry emergency equipment.

Does physical fitness protect against altitude sickness? No. Elite athletes can suffer altitude sickness while sedentary people feel nothing. There is no correlation with physical fitness.

Can I take Diamox without a prescription? In Peru it is sold without a prescription at pharmacies. But it is better to consult a doctor first, especially if you take other medications or are allergic to sulfa drugs.

Does coca tea really work? There is no solid scientific evidence, but it is part of Andean tradition and causes no harm. Many travelers report that it helps with mild symptoms.

What happens if I cannot continue the trek? Our guides will assess the situation. If necessary, we organize a descent and evacuation. Your safety is the priority.