Altitude Sickness in Cusco & Machu Picchu: Guide
Cusco sits at 3,400 m / 11,150 ft — high enough that most travelers feel altitude effects within a few hours of arrival. Machu Picchu itself is lower (2,430 m / 7,970 ft) and rarely triggers altitude sickness on its own, but most visitors arrive via Cusco. Acclimatization is the most important health planning step for your trip.
Symptoms to know
Mild Acute Mountain Sickness (AMS)
Feels like a mild hangover. Common in the first 24-48 hours.
- Headache (most common)
- Fatigue and weakness
- Mild nausea or loss of appetite
- Trouble sleeping
- Lightheadedness when standing
Moderate AMS
Persistent symptoms requiring rest and possibly medication.
- Persistent headache not relieved by ibuprofen
- Persistent vomiting
- Significant fatigue
Severe — descend immediately
- Difficulty walking straight (ataxia)
- Confusion or strange behavior
- Persistent shortness of breath at rest
- Pink or frothy sputum
- Bluish lips or fingertips
These can indicate HACE (high altitude cerebral edema) or HAPE (high altitude pulmonary edema) — both medical emergencies. Cusco has hospitals; descend and seek care immediately.
How to prevent altitude sickness
Before you arrive
- Talk to your doctor about acetazolamide (Diamox). Standard prophylactic dose: 125 mg twice daily, started 24 hours before ascent and continued 2-3 days after arrival at altitude.
- Be honest about pre-existing conditions: heart disease, hypertension, sleep apnea, sickle cell trait, severe anemia, recent stroke. Some require additional precautions.
- If pregnant, discuss the trip with your doctor; altitude is generally not recommended in late pregnancy.
On arrival in Cusco
- Take it slow the first 24 hours. No strenuous activity. Walk slowly. Climb stairs slowly.
- Hydrate aggressively. 3+ liters of water per day.
- Avoid alcohol on day 1 (it dehydrates and worsens AMS).
- Eat lightly and frequently — heavy meals at altitude often trigger nausea.
- Coca tea (mate de coca) — local remedy, mildly stimulant. Helps with appetite and mild headache. Available in every hotel.
- Sleep at lower altitude if possible — the Sacred Valley (2,800 m) is gentler than Cusco for first nights.
The "sleep at the Sacred Valley" trick
Many experienced travelers fly into Cusco, transfer immediately down to Ollantaytambo (2,800 m) or Urubamba (2,870 m), spend 2 nights there, then return to Cusco at the end. This drops the altitude during sleep — when AMS hits hardest — without sacrificing acclimatization for the rest of the trip.
Coca leaves and tea
Coca leaves are legal and openly available throughout Peru. Locals chew them with a small piece of llipta (alkaline ash) to extract the active compounds. Tourists usually drink them as tea (mate de coca). Effects are mild — a slight stimulant similar to a weak cup of coffee, plus appetite suppression and reduced altitude symptoms in some people.
Important: Coca is illegal in most countries outside the Andean region. Do not bring leaves or coca tea bags home. They will trigger drug-test positives and cause customs problems.
Sorojchi pills
Local pharmacies sell over-the-counter "Sorojchi" pills — typically a combination of acetylsalicylic acid (aspirin), salophen, and caffeine. They help mild headaches but do not replace acetazolamide for prevention. Use them for symptomatic relief, not as a primary preventive.
Oxygen
Many Cusco hotels have on-call oxygen for guests with severe symptoms. Some pharmacies sell small portable cans. If you genuinely need supplemental oxygen for more than a few minutes, descend.
Activities at altitude — order them sensibly
- Day 1: Arrive Cusco. Walk slowly around the historic center. Coca tea. Early dinner. Sleep.
- Day 2: Half-day in Cusco or transfer to Sacred Valley. Light sightseeing. Sleep at lower altitude if possible.
- Day 3: Sacred Valley sites (Pisac, Ollantaytambo).
- Day 4: Train to Aguas Calientes (this is a descent — feels easier).
- Day 5: Machu Picchu visit. The citadel itself is at moderate altitude and most people are fine.
Avoid heavy hikes (Wayna Picchu, Machu Picchu Mountain, anything in the Cusco area like Rainbow Mountain or Humantay Lake) on days 1-2. Save them for days 4+ once you're acclimatized.