Dealing with Altitude Sickness


Altitude Sickness


Altitude sickness is a common condition that can occur when you climb to a high altitude too quickly. It is frequently experienced when travelling from coastal regions (such as Lima) to cities with altitudes of 2500m (just over 8,200 feet) or more. Cusco lies at an altitude of 3360m so preventative measures should definitely be considered when arriving from Lima.

Altitudes of places of interest in Peru:

Lima 75m

Puerto Maldonado (Amazon Rainforest) 185m

Aguas Calientes 2040m

Arequipa 2350m

Machu Picchu Ruins 2400m

Start of the Inca Trail 2600m

Ollantaytambo 2795m

Urubamba 2870m

Pisac 2970m

Cusco 3360m

Puno (Lake Titicaca) 3809m

Highest pass on the Inca Trail 4200m (on the second day of the trek)

Causes and mild symptoms

As you climb in altitude the atmospheric pressure decreases and there is less oxygen in the air - basically the oxygen molecules are spaced much further apart so every lungful of air contains less oxygen compared to when you are at sea level. Because you aren't able to take in as much oxygen your breathing becomes more difficult. Nearly everyone arriving at Cusco (or Puno or Huaraz) on a flight from Lima will experience that the air feels "thinner". Your body automatically tries to compensate for the lack of oxygen by making you breathe faster and your heart beat faster, just as if you were doing exercise. You will notice that if you start to do anything remotely strenuous such as lifting your heavy bags off the luggage carousel at the airport you become tired much more quickly. For most people that's about as bad as it gets, just getting tired and out of breath quicker than normal. This feeling usually lasts only a couple of days as your body takes time to adapt and acclimatize to the change in altitude. During this acclimatization period some people can also experience mild symptoms of altitude sickness as indicated below. As long as you take things gently during these first few days and follow the advice given below in preventing altitude sickness then you should recover and be back to normal in a couple of days.

Mild symptoms of altitude sickness can include:

  • headache
  • nausea
  • dizziness
  • exhaustion
  • difficulty sleeping at night

Preventing altitude sickness

The best and most efficient way of avoiding problems with the high altitude is to ascend slowly. Instead to flying from Lima to Cusco you could consider an itinerary that spends a night or two in Arequipa and the Colca Canyon first. Arequipa is at 2350m so an ideal place to acclimatize. Alternatively, upon arrival at Cusco from Lima you could go immediately to the Sacred Valley and stay at a hotel in Urubamba or Ollantaytambo. One or two nights as this more gently altitude will make things easier for you when you go back to Cusco to stay. Lots of tour operators do this.

However most people still prefer to fly straight to Cusco and veryt few people have any serious problems with the high altitude as long as they take a few precautions. It's important to take things easy during the first 2 days in Cusco. Takes plenty of short rests and listen to your body. If you feel your heart is really pounding in your chest then its a sign you have to stop and have a break for a minute.

If you are trekking the Inca Trail to Machu Picchu then plan to spend at least 2 nights in Cusco prior to starting the trek. Don't plan to arrive in Cusco just one day in advance. The first day of the Inca Trail starts at 2600m and finishes at 3000m so the first day is relatively easy and can be considered as another day to acclimatize before reaching the highest point on the trek at 4200m on the second day. You'll certainly notice the lack of oxygen at this altitude but you won't spend long on the high pass as you decend to the valley floor when you camp for the night.

Keeping hydrated is very important. The air humidity is usually very low at high altitudes and can lead to a dry nose and mouth. You will lose moisture much quicker than if you were at sea level so you need to keep well hydrated. Drink plenty of fluids and avoid alcohol (at least for the first 2 nights). If you do have a glass of wine then follow it by at least 2 glasses of water. Don't smoke.

Using preventative medication

The information below has been taken from the National Health Service website in the UK. As with all medical advice the best source should be your doctor and not a travel forum which can often give conflicting and sometimes dangerous recommendations.


Research has shown that acetazolamide (Diamox, which is licensed to treat glaucoma) can help prevent symptoms of altitude sickness. It's thought that acetazolamide works by correcting the chemical imbalance of the blood, caused by ascending quickly to high altitude.
In the UK, acetazolamide is not licensed for preventing (or treating) altitude sickness. However, it may sometimes be considered for 'off-label' use to prevent altitude sickness in people who may be at risk of developing it.
To prevent altitude sickness, the recommended dose of acetazolamide is usually 125mg or 250mg twice a day. You should begin taking the medication one to two days before you start to ascend and continue to take it while ascending.
You may also be advised to take it for a day or two after you've reached your highest altitude. If you feel unwell while you're ascending, acetazolamide will not prevent you feeling worse and the only treatment is to descend or to rest.
There are a number of common but minor side effects associated with acetazolamide, including numbness or tingling of the face, fingers or toes. Some people find these quite distressing, so doctors often suggest trying it at home for two days before travelling if you're likely to use it at altitude.
You should let your doctor know if you have any allergies to any medicines before acetazolamide is prescribed. Your doctor will also check your medical history to see if acetazolamide is suitable for you.


Dexamethasone isn't usually recommended for preventing altitude sickness, but may be provided for the emergency treatment of high altitude cerebral oedema (HACE).

Mate de Coca (Coca leaf tea)

Mate de Coca

Mate de Coca is a herbal tea made using coca leaves and is frequently recommended to either prevent altitude sickness or to relieve the mild symptoms. It is greenish yellow in color and has a mild bitter flavor similar to green tea with a more organic sweetness. The leaves can also be chewed for a stronger effect. The coca leaf can provide physical and mental stimulation (in a similar way to caffeine) and frequently used by people living in the mountain communities to suppresses hunger, thirst, pain, and fatigue.

The leaves of the coca plant contain alkaloids which, when extracted chemically, are the source for cocaine base. Although the amount of coca alkaloid in one cup of coca tea is small I have read in a couple of places that it is enough to cause a positive result on a drug test for cocaine. Whether or not its true I can't say. Therefore it may be best to avoid drinking the tea if you are an airline pilot or train driver or have a job where you are frequently tested for drugs at work. From personal experience 20 years ago I worked as an engineer on the railways in the UK in what is known as safety critical work where I was subject to regular drugs and alcohol testing. Within three days of returning from a holiday in Peru in which I had drunk plenty of coca tea and chewed coca leaves whilst climbing I had a drugs test. The result was negative. Testing maybe more sensitive nowadays so I don't know if I would be quite so confident now. I would at least take a few photos of the mate de coca tea bags whilst on holiday and maybe consider informing your employer before a test just in case.

Buying Mate de Coca.

Coca leaves and coca leaf tea bags are perfectly legal in Peru, Bolivia and Ecuador. However they are not legal in the USA and Europe. You can buy Coca leaves in the San Pedro Market in Cusco as well as in most local markets. It is often more convenient to buy in the form of tea bags and can be bought in nearly all supermarkets throughout Peru including in Lima. Strangely enough, the shops at the international airport departures lounge in Lima also sell coca leaf tea in boxes of tea bags even though it is illegal to bring them into the US and Europe. I've taken a box of coca leaf tea to the UK several times but I always bought the box at the duty free shop at the airport in Lima, kept the receipt and then declared it at customs on arrival. I never had a problem, I guess that if you've declared it the worst that could happen is that they take it off you.

Pope Francis drinks coca leaf tea

Article extract from

It’s the brew of popes: coca, the main ingredient in cocaine, has been enjoyed by three popes. Pope Francis drank a tea of coca leaves, camomile and anise seeds on the plane to Bolivia from Ecuador this week, pope John Paul II drank tea made from coca leaves during his 1988 visit to Bolivia, and pope Paul VI drank the special tea during a visit to the Andes in 1968, according to the Catholic News Agency.

What to do if you have mild symptoms

If you have just arrived in Cusco then its fairly common to have some of the mild symptoms of altitude sickness such as a headache, getting out of breath quickly, lack of appetite and sometimes difficulty in sleeping. The best thing to do is follow the same advice for preventing altitude sickness. Don't try to do too much especially on the first day that you arrive in Cusco, avoid walking uphill, take plenty of rests and drink plenty of fluids such as water of coca leaf tea. Avoid any alcohol and don't smoke. You can take a painkiller for your headache. You should start to feel much better after the second or third day at altitude. You should also feel much better at lower altitudes such as in the Sacred Valley or even lower in Aguas Calientes & Machu Picchu. If moving to a hotel in the Sacred Valley my recommendation would be to go to Ollantaytambo because at least they also have a private medical clinic in case things get worse. Aguas Calientes also has medical facilities. However if your symptoms start to become more serious (see below) then it's best to seek medical advice at one of the private clinics in Cusco. Clinica Pardo is recommended.

More serious symptoms of altitude sickness

In rare cases altitude sickness can lead to a build up of fluid on the lungs or brain. These are very serious conditions and require immediate medical attention.

Severe symptoms of altitude sickness can include

severe breathlessness

bubbling sound in the chest

coughing up pink frothy liquid

disorientation, clumsiness and difficulty walking

What to do if you have serious symptoms

If you have any serious symptoms then you must seek medical attention immediately. If you are mountain climbing then don't wait to see if the person will get better, make a rapid descent and seek medical attention.

Clinica Pardo

Address: Avenida La Cultura 710, Cusco
Telephone: 256976 or 0989431050 (24hrs)
Location: Just 7 minutes by taxi from the Plaza de Armas, this clinic probably has the best facilities in Cusco and is a popular choice for tourists and ex-pats living in Cusco.

Who's affected by altitude sickness?

There are no specific factors, such as age, sex or physical fitness, that increases a person's likelihood of getting altitude sickness. Certain people are affected while others are less susceptible to it. Just because you haven't had it before doesn't mean that you won't develop it on another trip.

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