Real Symptoms, Scientific Prevention, and How to Avoid Risks at Altitude
Altitude sickness is one of the biggest concerns before undertaking the Salkantay Trek. And with good reason: the pass reaches 4,650 meters (15,000 feet). But here’s the truth that few explain well: most cases are mild and preventable if you prepare properly. In this 2026 guide, you’ll find everything you need to know—from symptoms to real protocols—to hike safely to Machu Picchu.
🌎 Why can the Salkantay Trek cause altitude sickness?
The Salkantay Trek is one of the highest treks in Peru.
Key Altitudes:
- Cusco: 3,400 m (10,000 ft)
- Humantay Lagoon: 4,200 m (14,000 ft)
- Salkantay Pass: 4,650 m (15,000 ft)
At that altitude, the available oxygen is approximately 40% lower than at sea level.
- The body needs time to adapt.
- The problem isn’t the altitude itself.
- The problem is ascending too quickly without acclimatization.
🧠 What exactly is altitude sickness?
Altitude sickness (AMS – Acute Mountain Sickness) occurs when the body fails to adapt properly to the decrease in oxygen.
It doesn’t depend on age or physical condition.
Even athletes can suffer from it.
⚠️ Symptoms of Altitude Sickness on Salkantay
🟢 Mild Symptoms (Most Common)
- Headache (main symptom)
- Nausea
- Unusual fatigue
- Mild dizziness
- Loss of appetite
- Mild difficulty sleeping
👉 These symptoms usually appear between 6–24 hours after the ascent.
🟡 Moderate Symptoms
- Persistent headache
- Vomiting
- Marked weakness
- Difficulty walking in a straight line
At this point, it is recommended to reduce your pace or descend slightly.
🔴 Serious Symptoms (Rare but important)
- Mental confusion
- Lack of coordination
- Persistent cough with shortness of breath
- Difficulty breathing even at rest
In these cases, immediate descent is mandatory.
📍 When is the Salkantay trek most critical?
The most demanding moment occurs on Day 2, when crossing the Salkantay Pass (4,650 m).
If you did not acclimatize beforehand in Cusco, the risk increases considerably.
📊 Technical Table – Risk by Altitude
| Altitude | Risk Level |
|---|---|
| 2,500 m | Low |
| 3,000 m | Moderate |
| 3,500 m | Moderate-High |
| 4,000 m | High |
| 4,650 m | Very High |
The Salkantay trek combines several levels of risk in just a few days.
🧭 How to Prevent Altitude Sickness (Complete Strategy)
🏔️ 1. Smart Acclimatization (The Absolute Key)
Stay in Cusco for at least 2–3 days before the trek.
Ideal Recommendation:
- Day 1: Light rest
- Day 2: Easy hike
- Day 3: Moderate activity
Never arrive in Cusco and start the trek the next day.
💧 2. Strategic Hydration
- Drink 2–3 liters of water daily
- Add electrolytes
- Avoid alcohol and excessive coffee
Dehydration worsens symptoms.
🍽️ 3. Proper Nutrition
- Complex carbohydrates
- Avoid heavy meals
- Eat small, frequent meals
💊 4. Preventive Medication
- Some travelers use:
- Acetazolamide (consult a doctor first)
Ibuprofen for mild pain
In Peru, coca tea is commonly used as a traditional aid, although its effect is mild compared to proper acclimatization.
🐢 5. Slow and Steady Pace
Golden rule:
“Climb slowly, breathe deeply.”
Don’t compete with other hikers.
🏕️ Does hiking independently or with a tour make a difference?
With an organized tour:
- Guides trained in first aid
- Constant monitoring
- Pace adjustment
- Evacuation plan
- Altitude sickness kit
On your own:
- Full individual responsibility
- Greater risk if you have no experience
For most international tourists, an organized tour significantly reduces risks.
🌦️ Does the Season Matter?
The weather doesn’t cause altitude sickness, but it does influence the experience.
☀️ Dry Season:
- Colder at the pass
- Less humidity
- More stable conditions
🌧️ Rainy Season:
- More physical exertion
- Greater fatigue due to mud
The extra effort can aggravate mild symptoms.
💰 Transactional Value: Safety and Costs
💵 Average Price of the Salkantay Trek
- USD 550 – 900 (standard)
USD 900 – 1,500 (premium)
✅ Generally Includes
- Certified guide
- Basic health monitoring
- Transportation
- Camping
- Entrance to Machu Picchu
- Return train
❌ Does Not Include
- International medical insurance
- Specific medication
- Private air evacuation
Travel insurance with altitude coverage is highly recommended.
🎒 Advanced Pro-Tips for Foreigners
🏔️ 1. Don’t underestimate Cusco
3,400 m is already a considerable altitude.
🧥 2. Keep warm
Cold can worsen feelings of discomfort.
💧 3. Clear urine = good hydration
A simple but effective indicator.
🛌 4. Get plenty of rest before day 2
This is the most critical day.
🧠 5. Listen to your body
Ego is your worst enemy at altitude.
🤔 What percentage of people suffer from altitude sickness?
Statistically:
- 25–50% may experience mild symptoms.
- Less than 5% develop severe symptoms.
Most people improve with rest and hydration.
Altitude sickness on Salkantay is a real risk, but entirely manageable.
The formula for avoiding problems is clear:
✔ Acclimatization for 2–3 days
✔ Constant hydration
✔ Controlled pace
✔ Travel insurance
✔ Listen to your body
With proper preparation, Salkantay is safe and one of the most breathtaking experiences in Peru.
