Guide · Cusco
Altitude sickness in Cusco
Cusco sits at 3,399 m. At that height every breath carries about a third less oxygen than at sea level, and the body takes one to three days to compensate. Here is what is normal to feel, what is not, and how to sequence a trip so that altitude gets in the way as little as possible.
This page is informational and does not replace medical advice. If you have heart or lung disease, are pregnant, or take regular medication, discuss it with your doctor before travelling to altitude.
What is normal to feel
It appears 6 to 12 hours after you arrive. It is called soroche here and acute mountain sickness in the medical literature. It happens to plenty of healthy people and it passes on its own.
- Headache, which is the central symptom
- Breathlessness going up a hill or a flight of stairs
- Tiredness out of all proportion to what you did
- Little appetite, some nausea
- Broken sleep, waking repeatedly, a smothering feeling as you drop off
- A faster heartbeat at rest
With rest, water and no further ascent, this improves within one to three days. If it gets worse instead of better, it has stopped being ordinary acclimatisation.
When to stop waiting and go down
These signs are not "bad soroche": they point to fluid building up in the lungs or the brain and they are medical emergencies. The treatment is descent, and it has to be prompt, alongside medical attention. None of them resolves by sleeping it off until morning.
Breathlessness while at rest
Feeling short of breath sitting or lying down, not while walking. Often with a dry cough or wheeze.
Frothy or blood-tinged cough
Any pink or foamy sputum. This is an emergency, not an altitude cold.
Loss of balance
Unable to walk in a straight line, staggering, or unable to stand with feet together and eyes closed.
Confusion or odd behaviour
Talking nonsense, not knowing where they are, drowsiness that will not clear. This is never just tiredness.
A headache that will not lift
Severe pain that does not respond to ordinary painkillers, especially with repeated vomiting.
Blue lips or fingernails
Along with a very fast pulse at rest. A sign that blood oxygen is falling.
On the route, tell your guide immediately. In Cusco there are clinics with 24-hour emergency cover; we go with you and arrange the transfer. Descending 500 to 1,000 m usually turns things around within hours.
The first 48 hours
Arrive and do nothing
The afternoon you land is for walking slowly, eating light and sleeping early. It sounds obvious and it is the part most often ignored: what you do in those first hours is what separates a mild headache from two lost days.
No alcohol for the first 24 to 48 hours
Alcohol suppresses breathing exactly when your body needs to breathe more, and dehydrates you on top of that. The welcome pisco sour is the custom that sits worst with altitude.
Eat little and often
Light, frequent meals rather than one heavy lunch. At altitude digestion competes for the oxygen the rest of the body needs, and a large first-day meal usually ends in nausea that gets mistaken for altitude sickness.
Drink far more water than you would ask for
Dry air and faster breathing take fluid out of you without your noticing. Two or three litres a day in the first days is normal, and it helps you tell a dehydration headache from a genuine altitude one.
No sleeping pills
Common sleeping aids suppress breathing overnight, which is when your oxygen level drops furthest. Sleeping badly for the first two nights in Cusco is normal and passes on its own.
Being fit does not protect you
This is the most repeated myth of all. A marathon runner gets ill just as easily as someone sedentary, sometimes more so, because they push the pace on day one. Altitude does not care about training; it cares about how fast you went up.
Where you sleep matters more than where you climb
The body acclimatises overnight. That is why spending your first night in the Sacred Valley, half a kilometre lower, helps more than any remedy — and why Machu Picchu causes no altitude trouble even though people expect the opposite.
| Place | Altitude | What it means |
|---|---|---|
| Lima | 0 m | Sea level. Flying from here to Cusco means gaining 3,400 m in an hour. |
| Aguas Calientes | 2,040 m | The town below Machu Picchu. You sleep better here than in Cusco. |
| Machu Picchu | 2,430 m | Almost a thousand metres below Cusco. It surprises nearly everyone. |
| Ollantaytambo | 2,792 m | A good first night if you reach the valley early in the day. |
| Urubamba, Sacred Valley | 2,871 m | Half a kilometre lower than Cusco. Acclimatisation goes better here. |
| Cusco | 3,399 m | The city itself, where most people spend the two hardest nights. |
How high each tour goes
Highest first. The ones that ask for acclimatisation days say so on their page, and that number is not a suggestion: it is the minimum at which the route is enjoyed rather than endured.
| Tour | Maximum altitude | Days in Cusco first |
|---|---|---|
| Rainbow Mountain — Vinicunca | 5,036 m | 2 |
| Palccoyo — Rainbow Mountain | 4,900 m | 1 |
| Seven Lakes of Ausangate | 4,600 m | 2 |
| Inca Jungle — 4 Days | 4,316 m | 1 |
| Waqrapukara | 4,300 m | 2 |
| Humantay Lake | 4,200 m | 2 |
| Sacred Valley of the Incas | 3,762 m | — |
| Cusco City Tour | 3,700 m | — |
| South Valley — Tipón, Pikillacta and Andahuaylillas | 3,560 m | — |
| Maras, Moray and the Salt Pans | 3,500 m | — |
| Machu Picchu — 2 Days | 3,400 m | 1 |
| Machu Picchu Full Day | 2,430 m | 1 |
What actually helps, of everything you will be offered
Coca tea
The first thing your hotel will offer you, and it does no harm — but it helps to know what it is and is not. It eases the discomfort a little and settles the stomach; it does not prevent altitude sickness and it is no substitute for acclimatising. One practical point: it can show up on a drug test, and taking coca leaf out of the country is a criminal offence in most destinations.
Pharmacy "soroche pills"
Sold in any chemist in Cusco. They usually combine a painkiller with caffeine: they take away the headache, which is the symptom, and change nothing about what causes it. Useful, but not a licence to go up faster.
Acetazolamide
This is the drug that genuinely speeds up acclimatisation, and it is prescription-only. It is started before you go up, has contraindications — a sulfa allergy among them — and side effects worth knowing about in advance. Talk to your doctor at home before you travel; we do not prescribe and we do not suggest doses.
Oxygen
It relieves symptoms while it is being used, and it is what we carry on every high-altitude departure. It does not cure: if the symptoms return once it is removed, the answer is not more oxygen, it is descending.
Frequently asked questions
- How long does it take to pass?
- The usual discomfort appears 6 to 12 hours after arriving and clears on its own within one to three days, as long as you do not keep going higher. If it gets worse rather than better on the second day, that is no longer acclimatisation in progress and you should get it looked at.
- Is Machu Picchu high?
- No, and it is the biggest surprise of the trip: the citadel sits at 2,430 m and the town of Aguas Calientes at 2,040 — almost a thousand metres below Cusco. Plenty of people who feel rough in the city feel perfectly fine on their Machu Picchu day.
- What about Rainbow Mountain?
- That one is high. Vinicunca is above 5,000 m and is the highest point any day tour from Cusco reaches. It is not a day-one or day-two outing, however freely it is sold as a full day on any given morning. If time is short, Palccoyo reaches a similar landscape with less altitude and far less walking.
- Is it worth sleeping the first night in the Sacred Valley?
- If your flight lands early, yes. Urubamba is at 2,871 m and Ollantaytambo at 2,792, some 500 m below Cusco, and what matters most for acclimatising is the altitude you sleep at, not the highest point of your day. Coming back up to Cusco after two nights lower down makes a real difference.
- I have a medical condition. Can I go?
- Your doctor answers that, not a travel agency. If you have heart or lung disease, are pregnant, have sickle cell anaemia or take regular medication, ask before you buy the flights. Tell us what you were advised and we will build the itinerary around it.
- What happens if I get ill on a high-altitude day?
- Your guide carries a first aid kit and oxygen, and makes the call. If rest and oxygen do not improve things, an accompanied descent is arranged to the nearest accessible point. That decision belongs to the guide on safety grounds and is not negotiated with the group.
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