Cusco at 11,000 Feet: I Prepared and the Altitude Still Broke My Plans

Cusco sits at roughly 11,150 feet above sea level. You can look up that number in advance. You can read about altitude sickness, hydration, coca tea, and rest days. You can train. I did all of that. I flew in prepared, medicated, hydrated, and optimistic. I still learned quickly that altitude in Cusco is not something you manage once and move on from. It’s something you bargain with hour by hour.

This article is an account of what it actually felt like to arrive in Cusco, confident and prepared, and still be forced to slow down in ways I didn’t anticipate. It’s about fear that arrived quietly in the middle of the night, about learning when numbers lie, and about listening to your body when you would rather power through.

If you’re researching Cusco altitude sickness, oxygen levels, asthma at high altitude, or how to acclimate without ruining your trip, you’re in the right place. What follows is not medical advice. It’s lived experience, including counsel given to me by local clinicians.

From Florida Heat to Andean Thin Air

I landed in Cusco in July 2025 after a long chain of flights from Orlando, with layovers in Bogotá and Lima. I stepped out of the small airport, pulled on a coat, and immediately felt the difference. Summer at sea level does not prepare you for winter in the Andes.

My Airbnb was on Calle Saphi, a few minutes walk from Plaza de Armas, the main square of the city’s historic center. Close enough to feel central. High enough to feel the rush of being alive here. I checked in, dropped my bag, and went out to orient myself. The city was beautiful, busy, and indifferent to my arrival

Preparation Does Not Mean Immunity

I didn’t arrive naive. Weeks before the trip, I increased my cardio. I spoke to my doctor. I obtained a prescription for acetazolamide (Diamox) and began taking it two days before landing. I packed my rescue inhaler. I did all this because I had history.

Years earlier, in Keystone, Colorado, I had been hospitalized with high-altitude pulmonary edema (HAPE). That experience never really leaves you. It will be remembered whenever you return to high altitudes.

When symptoms began within hours of arriving in Cusco, I wasn’t surprised. Headaches, dizziness, fatigue, accelerated heart rate, and shortness of breath all appeared; not suddenly, but steady and lingering. I drank water. I drank electrolytes. I ordered mate de coca (coca tea). I slowed down.

At first, I told myself this was normal, and it was. The problem wasn’t the symptoms. The problem was what happened when I started measuring them.

The Pulse Oximeter Problem

I brought a pulse oximeter with me. At sea level in Florida, my oxygen saturation typically sits between 96 and 99 percent. In Cusco, it did not.

The readings hovered in the high 80s. Then lower. Then lower still. What I did not know yet was that cold hands can produce wildly inaccurate readings. My Airbnb was freezing. The space heater was inadequate. I later learned that the oximeter was lying to me, but at the time, I believed it completely. Numbers have authority, even when they’re wrong.

The Night Everything Changed

On my second night in Cusco, fear became real.

I was exhausted and afraid to fall asleep. Oxygen readings were low. My hands were cold. At some point, I drifted into an uneasy half-sleep with the oximeter still on my finger. I dreamed that it displayed an urgent warning, something like “seek medical attention immediately.” Even now, I’m not sure if that was just a dream.

I woke up and my brain said, very clearly: “If I fall asleep, I won’t wake up.”

That thought rearranged everything.

I got up. I drank electrolytes. I made coca tea. I waited for the sun. When morning came, I showered, packed my bag, and left the apartment. I found a small boutique hotel with good reviews and asked the front desk clerk two questions, “Do you have heat? Do you have hot water?”

They did. Sold! That was enough. I was being practical. I needed warmth, sleep, and proximity to people who had seen this before. I realized that it was time to distinguish danger from discomfort. My oxygen levels began to improve.

What Clinics in Cusco Actually Told Me About Oxygen Levels

Later, I went to a traveler medical clinic in Cusco. The care was excellent, fast, and far more affordable than anything I’m used to in the United States. They confirmed what I had since learned.

Clinicians explained that oxygen saturation at altitude is often lower than what people are used to at sea level. Fully acclimated individuals often live with numbers that would alarm a sea level doctor. I was informed what mattered was not a single reading, but symptoms and trends. They also confirmed that cold hands can distort readings.

The doctor prescribed additional acetazolamide and a concentrated electrolyte drink. He also made it clear that seeking care is the right move if symptoms worsened or readings stayed persistently low.

Asthma, Altitude, and Knowing the Difference

I am asthmatic. At sea level, it’s mostly triggered by illness, allergens, or chemicals. In Cusco, it felt different.

The headaches were new. The fatigue was deeper. The breathlessness was layered with tachycardia (heart rate over 100 beats a minute). But there was no fluid sensation in my lungs, no crackling, no progression toward the symptoms I experienced in Colorado.

That distinction mattered. It allowed me to calm down. It also reinforced the importance of familiarity with your own body.

I used my inhaler regularly. I took acetazolamide twice a day. I rested more than I wanted to. I bought portable oxygen canisters almost daily. They helped, not because they solved everything, but because they helped me cope with the strain of low oxygen levels.

Cusco at a Slower Pace

Moving slowly through Cusco changed how I saw it. The city did not feel rushed or impatient. Locals moved steadily, climbing hills and breathing normally. No one looked winded. The contrast was humbling.

I thought often about the porters and guides who work in these elevations daily, for whom this is not a bucket-list challenge but a routine. I wondered about their adaptation and about what it means to grow up somewhere your lungs learn from childhood.

What Helped, What Didn’t

Here is what actually helped me acclimate in Cusco:

• Hydration and electrolytes, consistently

• Coca tea, especially when paired with rest

• Acetazolamide, begun before arrival and continued until returning to low altitude

• Portable oxygen, used sparingly

• Small, delicious meals

• Warmth and sleep

Here is what did not help as much as expected:

• Assuming physical training alone would compensate for thin air

• Over-relying on numbers

Strength training and stair workouts did not prepare my heart for an already elevated baseline. Two flights of stairs could feel like a sprint.

The Itinerary I Had to Let Go Of

I planned to complete the four-day Lares Trek to Machu Picchu. I did not.

I skipped the first two days of the trek entirely. Instead, I stayed longer in Cusco than planned, acclimating slowly. On day seven of the trip (would’ve been day three of the trek), I joined a Sacred Valley tour, visiting the Maras Salt Mines, Ollantaytambo, the only Inca town continuously inhabited, and other Sacred Valley sites. I then took the train to Aguas Calientes to meet my guide for the final approach.

I arrived at Machu Picchu the following morning. It may not have been the way that I wanted to arrive, but this adjustment likely prevented hospitalization or worse. It also forced me to confront a difficult truth. Sometimes preparation does not earn you the outcome you want.

Cusco Is Not a Place to Prove Anything

There is a temptation to treat high altitude treks as a test of toughness. Cusco rejected that framing for me. Staying alert to your body, adjusting plans, and asking for help is not weakness. It is respect for the land and for yourself.

Cusco taught me that my body is not going to lie to me, and it is not to be ignored. It is adaptable, but only when informed and listened to.

If you are coming here, come prepared.

Frequently Asked Questions About Cusco Altitude

Is Cusco altitude sickness common?

Yes. Many travelers experience symptoms due to Cusco’s elevation. Severity varies widely.

What oxygen saturation is normal in Cusco?

Clinics explained that oxygen levels are often lower at altitude than at sea level. Context, symptoms, and trends matter more than a single number.

Does Diamox help with Cusco altitude sickness?

For many people, acetazolamide helps reduce symptoms when started before arrival. I believe that it helped me. My symptoms were milder than when I had HAPE in Colorado, although Cusco is approximately 1,900 ft (about 580 m) higher than Keystone. Consult a doctor.

Is coca tea effective?

Many travelers, including me, found it helpful for mild symptoms when combined with hydration.

Should people with asthma avoid Cusco?

No, not necessarily. Preparation, medical consultation, and caution are advised.

Final Thoughts

Cusco is extraordinary, not despite the altitude, but partly because of it.