Mild symptoms typically ease within 12–48 hours as your body acclimatizes. If symptoms persist beyond 2–3 days or worsen, you should descend and consider seeing a doctor.
Everything you need to know about soroche before exploring Cusco, Rainbow Mountain and the high Andes — how to prevent it, recognize it, and travel safely above 3,000 meters.
Cusco sits at 3,400 m (11,150 ft) — higher than many travelers have ever been. The good news: with the right preparation, the vast majority of visitors adjust within a day or two and go on to hike Rainbow Mountain, the Inca Trail and beyond without trouble. This guide tells you exactly how.
Altitude sickness — known locally in the Andes as soroche — happens when your body struggles to adjust to the lower oxygen levels found at high elevations. The air at 3,400 m contains roughly one-third less oxygen than at sea level. Your body compensates by breathing faster and producing more red blood cells, but this adjustment takes time.
The medical term is Acute Mountain Sickness (AMS), and it can begin to affect people at elevations above about 2,500 m. It has nothing to do with fitness — marathon runners can get it while their less-athletic friends feel fine. It is simply about how quickly your particular body adapts.
Symptoms usually appear 6 to 24 hours after arriving at altitude and range from a mild nuisance to a genuine emergency. Knowing the difference is the single most important thing you can learn.
Affects a large share of visitors during their first day in Cusco. Uncomfortable, but it resolves with rest and time. You can stay at your current altitude — just don't go higher until it passes.
Symptoms intensify and over-the-counter painkillers no longer help much. This is a clear signal to stop ascending, rest, and consider descending if things don't improve within 24 hours.
High-Altitude Pulmonary Edema (HAPE) is fluid in the lungs; High-Altitude Cerebral Edema (HACE) is swelling of the brain. Both are rare but life-threatening and require immediate descent and medical care.
Anyone ascending quickly to high altitude can develop AMS, but a few factors increase the odds:
Importantly, age and fitness are poor predictors. Children and older travelers manage altitude every day in Cusco; the key is sensible acclimatization, not athletic ability.
Knowing the elevation of each destination helps you plan a sensible order. Acclimatize low, then climb high.
| Place | Altitude | Risk level |
|---|---|---|
| Lima (sea level) | 0 m | None |
| Sacred Valley (Urubamba) | 2,870 m | Low |
| Machu Picchu | 2,430 m | Low |
| Cusco city | 3,400 m | Moderate |
| Humantay Lagoon | 4,200 m | Moderate |
| Dead Woman's Pass (Inca Trail) | 4,215 m | Moderate |
| Rainbow Mountain (Vinicunca) | 5,030 m | High |
| Ausangate & Qelcaya | 5,000–5,200 m | High |
Notice that Machu Picchu is actually lower than Cusco — many travelers feel better there. A smart first week starts in the Sacred Valley (lower than the city), which is why we often recommend it before the high-altitude classics.
Prevention is far easier than treatment. These steps dramatically reduce your chances of a rough first few days:
Acetazolamide (Diamox) is the most widely used preventive drug. It speeds up your body's natural acclimatization and is often started a day before ascending. It is a prescription medication — talk to your doctor about whether it's right for you, and never self-prescribe. Simple painkillers like ibuprofen or paracetamol can help with altitude headaches. Inkanet guides carry emergency oxygen and a pulse oximeter on every high-altitude tour.
If you feel unwell, assume it's the altitude until proven otherwise. Don't dismiss symptoms as just a hangover or tiredness.
Never ascend further with symptoms of AMS. Wait where you are until you feel better before going any higher.
If symptoms get worse, descend immediately. Going down even 300–500 m almost always brings rapid relief. Descent is the cure.
For mild AMS, the treatment is simple: stop, rest, hydrate, and give your body time. Painkillers ease the headache; anti-nausea medication can settle your stomach. Most people feel noticeably better within 12–24 hours.
For moderate symptoms, the same applies but with a lower threshold to descend. Supplemental oxygen — available at most Cusco hotels and pharmacies, and carried by our guides — provides quick temporary relief.
For any sign of HAPE or HACE, there is only one answer: descend at once and get emergency medical care. These conditions can worsen within hours.
Treat the following as a medical emergency. Begin descending immediately and seek help:
In Peru, dial 116 for emergencies. On any Inkanet tour, your guide is trained to recognize these signs, carries oxygen, and will coordinate an immediate descent and medical response.
Every Inkanet high-altitude tour includes certified guides trained in altitude first aid, emergency oxygen and a pulse oximeter — so you can focus on the view.