How to Avoid Altitude Sickness in Cusco

Pre-Trip Preparation · 1–2 Weeks Before Departure

The most effective preparation for altitude begins before you leave home. If you have any cardiovascular or pulmonary conditions, consult your doctor before booking a trip to Cusco. Discuss acetazolamide (Diamox) — a prescription medication commonly used to prevent AMS — with your physician. It is most effective when started 24–48 hours before ascending to altitude and continued for 48 hours at elevation. Note that it is a diuretic and increases urination, so hydration is essential. Aspirin (one tablet the evening before arrival and the morning of arrival) is also used by many travellers to reduce headache severity.

Arrive in good general health: avoid alcohol in the 24 hours before flying, stay well-hydrated during the flight, and get a full night's sleep the night before your Cusco arrival.

Tip: Do not attempt to self-prescribe Diamox — it has contraindications and is a sulphonamide derivative. Always consult a physician before use.

Travel Route Strategy · Lima → Arequipa → Cusco

The most important factor in preventing serious AMS is how you arrive in Cusco. Flying directly from Lima (sea level) to Cusco (3,400 m) in two hours is a severe altitude jump — it is the approach most likely to cause significant symptoms. The better strategy is to spend 2–3 nights in Arequipa (2,335 m) first, allowing your body to begin adjusting before the final ascent. Travellers following the full Peru loop (Lima → coast → Arequipa → Cusco) naturally benefit from this graduated ascent.

If you must fly directly to Cusco, plan your first full day as a complete rest day: no tours, no walking the steep cobblestone streets, no alcohol, and no strenuous activities. Even if you feel fine on arrival, your body is working hard internally. The second day can include gentle walking and a half-day cultural tour. Reserve strenuous hikes for day three onwards.

Tip: Book your Cusco accommodation for at least one extra night beyond your original plan — AMS often delays the start of activities by a day, and rushing is the surest way to worsen symptoms.

Daily Habits · Essential Throughout Your Stay

Drink at least 3 litres of water per day while in Cusco and the Andes. Altitude increases respiration and perspiration, and dehydration worsens every symptom of AMS. Carry a water bottle at all times and refill it constantly. Avoid alcohol entirely for the first 48 hours — it dehydrates you, impairs sleep quality, and dilates blood vessels in ways that worsen headaches at altitude.

Eat lightly during the first day or two: heavy meals divert blood flow to the digestive system and can increase nausea. Soups, light carbohydrates, and fruits are ideal. Avoid fatty, rich, or very spicy foods until you are acclimatised. Peru's traditional cuisine at altitude — soups like caldo de gallina (chicken broth), quinoa soup, and simple potato dishes — is genuinely well-suited to the physiological demands of the high Andes and has been so for thousands of years.

Tip: Avoid diuretics including coffee during the first 24 hours, or at least increase your water intake proportionally if you cannot skip your morning coffee.

Andean Tradition · Legal in Peru · Widely Available

Coca tea (mate de coca) is the most widely recommended traditional remedy for altitude sickness across the Andes and has been used by indigenous communities for thousands of years. It is made from the dried leaves of the coca plant, is entirely legal in Peru and Bolivia, and is served freely in virtually every hotel, restaurant, and guesthouse in Cusco. Most travellers find it helps reduce headache intensity and nausea, though controlled scientific studies on its efficacy are limited.

Other traditional preparations include chewing coca leaves directly (the traditional method) and sorojchi pills, an over-the-counter Peruvian remedy available in pharmacies throughout Cusco and the Andean region. Sorojchi pills typically contain aspirin, caffeine, and an antiemetic — they address symptoms rather than underlying physiology but provide meaningful relief for many travellers.

Important: Coca leaves and coca tea contain trace alkaloids and will show a positive result on drug tests for cocaine. If you are subject to workplace drug testing, do not consume coca products. The alkaloid quantities are extremely small, but testing equipment may detect them.

Tip: Your hotel in Cusco will almost certainly offer a welcome cup of coca tea on arrival. Accept it — it is a genuine gesture of hospitality and a sensible first step.

Sacred Valley · Machu Picchu · Rainbow Mountain · Timing

One of the great advantages of the Cusco region's geography is that its most popular site — Machu Picchu — is actually lower than Cusco itself, at 2,430 m. A visit to Machu Picchu after two or three nights in Cusco will feel like a genuine relief: thicker air, more energy, and no altitude concerns. The Sacred Valley (2,800–3,500 m) is also comfortable after initial acclimatisation and is a popular choice for travellers who want to ease into the altitude gradually before staying in Cusco itself.

Rainbow Mountain (5,200 m) should only be attempted after at least 3 nights at altitude above 3,000 m. The trail itself is not technically difficult, but the altitude at the summit is extreme. Laguna Humantay (4,200 m) is more accessible and appropriate for travellers who have acclimatised for 2–3 days. Laguna 69 in the Cordillera Blanca (4,600 m) requires similar preparation if you plan to visit northern Peru.

Tip: Schedule your Machu Picchu visit for your third or fourth day in the Cusco region — the lower altitude will feel like a reward after the initial acclimatisation effort.

When to Act · HAPE and HACE · Immediate Descent

Most AMS resolves with rest. However, certain symptoms indicate a medical emergency requiring immediate descent and professional medical care. Seek medical attention urgently if you experience: severe headache unresponsive to pain relief; loss of coordination or inability to walk in a straight line; confusion, unusual drowsiness, or disorientation; shortness of breath at rest (not just during exertion); a persistent dry cough, especially if accompanied by a bubbling or crackling sound; or any chest tightness or pressure.

These symptoms may indicate High-Altitude Pulmonary Edema (HAPE — fluid in the lungs) or High-Altitude Cerebral Edema (HACE — fluid on the brain), both of which are life-threatening. The only definitive treatment is immediate descent. Do not wait to see if symptoms improve at altitude — descend immediately and seek a physician. Cusco has several hospitals and clinics familiar with altitude-related illness, and hyperbaric chambers are available at the airport clinic.

Tip: Never ascend to a higher altitude with symptoms of AMS. The rule in high-altitude medicine is: if in doubt, go down.

Older Travellers · Children · Medical Conditions

Age itself is not a reliable predictor of altitude tolerance — some older travellers acclimatise without difficulty while younger, fit travellers struggle. However, older adults and those with pre-existing cardiovascular, pulmonary, or haematological conditions should consult a physician thoroughly before planning a trip to Cusco and seek advice specific to their health profile. People with anaemia, heart conditions, or chronic respiratory disease face elevated risks at altitude and should plan with particular care.

Children are generally more resilient than adults at altitude and their symptoms can be harder to identify. Keep children well-hydrated, watch for unusual fatigue, refusal to eat, or persistent crying, and descend without hesitation if their condition deteriorates. Pregnant women should avoid travelling to very high altitudes without specific medical guidance — reduced oxygen can affect foetal development.

Tip: If travelling with older relatives or young children, plan an extra acclimatisation day and keep excursion distances conservative for the first three days.