How to Prevent Altitude Sickness When Traveling

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Health and safety should be your first priority as a solo female traveler, though one thing many of us overlook when traveling to regions with high altitudes is the risk posed from altitude sickness.

Travelers to the Himalayas, Tibet, Nepal, the Andes, Mount Kilimanjaro and Mount Kenya, the Rocky Mountains, or those taking on famous treks like Everest Base Camp and the Inca Trail should be aware of this. Other high altitude destinations also include Cochabamba in Bolivia, Bogota in Colombia, Quito in Ecuador, and Cuzco in Peru.

Simply put, when you’re traveling to destinations over 2,500 metres, your lungs need time to adjust to reduced oxygen and breathing thinner air. Otherwise altitude sickness kicks in.

What is Altitude Sickness?

Female mountain climber RF

As you travel to high altitudes, the amount of oxygen in the air you are breathing declines. Altitude sickness is our body’s response to the low air pressure and reduced oxygen; less oxygen reaches the muscles and the brain, and the heart and lungs must work harder to compensate. This is a potentially serious disease, though is preventable with proper acclimatization.

Typically, altitude sickness occurs at altitudes over 2,500 metres (8,000 ft), though most people can ascend to 2,500 metres with little or no effect. At over 3,000 metres (10,000 feet) 75% of people will develop mild symptoms.

Symptoms of Altitude Sickness

Symptoms start 12 to 24 hours after arrival and begin to decrease in severity around the third day. You may develop a headache, lassitude, insomnia, loss of appetite, nausea and vomiting. These symptoms are collectively referred to as acute mountain sickness (AMS) and perfectly imitate the feeling of a bad hangover. What does altitude sickness feel like?

Serious symptoms do not usually occur until over 3,600 meters (12,000 ft), an altitude which is considered extremely high. In rare cases, fluid can build up either on the lungs, brain or both which could cause a bubbling sound in the chest, worsening breathlessness, coughing up pink, frothy liquid, clumsiness and difficulty walking and/or confusion leading to loss of consciousness.

These are advanced forms of AMS referred to as High Altitude Cerebral Oedema (HACE) and High Altitude Pulmonary Edema (HAPE) and should be treated as a medical emergency. In this case the best form of treatment is to immediately descend to a lower altitude and seek medical help.

If you know that you are going to be traveling to high altitudes, follow a few simple steps to prevent altitude sickness.

How to Prevent Altitude Sickness

The best way to avoid getting sick is to ascend gradually, but if you have to ascend quickly, medicines are available to prevent altitude sickness.

Anyone can suffer from altitude sickness – it does not discriminate between age, gender, level of fitness or training. For instance AMS is actually more likely to affect fit young women who attempt a rapid ascent by racing up the mountain like some indestructible super hero! Even at the most extreme heights, it’s not necessarily the height that is important, rather the speed in which you ascended to that altitude.

For this reason, travelers who drive, ride or fly to high altitude sites in the Andes and the Himalayas are more at risk than those who walk in.


The main cause of altitude sickness is going too high too quickly. Given enough time, your body will adapt to the decrease in oxygen at a specific altitude. This is known as acclimatization. How to acclimatize to high altitudes?

The only way to avoid or cure for altitude sickness is either acclimatization or descent. Ascending slowly will give your body time to learn to cope with decreased oxygen. It usually takes a few days for the body to get used to this change, so those who fly into high altitude must be prepared to spend time acclimatizing on arrival.

Don’t exercise, don’t smoke, and plan for plenty of rest until you feel better. High carbohydrate diets often work well for alleviating acute altitude sickness symptoms as well as improving mood and performance, so be sure to eat appropriately.

Also, drink plenty of fluids, though avoid alcohol or caffeinated products such as energy drinks or sodas as these can dehydrate your muscles. The body’s water losses increase during an active day in the dry cold air at high altitude, therefore, keeping hydrated is important (you may need as much as 4-7 litres per day).

It’s a good idea to tell people you’re travelling with how you feel, even if your symptoms are mild. This will help them be more aware of signs of severe sickness, such as irrational behaviour, if you develop them. If altitude sickness becomes worse, you must immediately descend to a lower altitude.

Pro tip: As an alternative, consider taking a day trip to a higher altitude. It’s less risky to take a day trip to a higher altitude and then return to a lower altitude to sleep.

It is highly advisable not go over 9,000 feet in altitude in 1 day. Instead, spend a few days at 8,000–9,000 feet before proceeding to a higher altitude to give your body time to adjust to the low oxygen levels. Do not sleep 1,000 to 2,000 feet above the altitude you slept at the previous night. You should always spend an extra day acclimating for every 3,300 ft.

It is important to listen to your body when traveling to high-altitude locations, since altitude sickness can be serious. If you suspect that you are experiencing altitude sickness, don’t go any higher until your symptoms improve and move to lower ground if your symptoms get worse.


It is important to note that there is no substitute for proper acclimatization. Medicines are available to shorten the time it takes to get used to high altitude, however, people with altitude sickness should not continue to ascend until they have gotten used to the altitude.

Critically, a person whose symptoms are getting worse while resting at the same altitude must descend or risk serious illness or death. Drugs to prevent AMS often only hide the warning symptoms as opposed to curing the problem, so in general it is much safer to rely on good planning and gradual ascent rather than medication.

That being said many high-altitude destinations are remote and lack access to medical care, so preventing altitude illness is better than getting sick and needing emergency treatment. Available medications include the following:


Painkillers, such as paracetamol or ibuprofen, can be used to treat mild headaches caused by altitude sickness.

Anti-sickness medication

If you’re experiencing nausea or vomiting, a type of medication called an anti-emetic may be useful. Promethazine is an anti-emetic medicine often used by people with altitude sickness.

Acetazolamide (Diamox)

This is the most tested drug for altitude sickness prevention and treatment. Unlike dexamethasone (below) this drug does not mask the symptoms but actually treats the problem.

Diamox makes your blood more acidic correcting the chemical imbalance brought on by altitude sickness. Acidifying the blood drives the ventilation, which is the cornerstone of acclimatisation. You are able to breathe faster so that you metabolise more oxygen.

Minor side effects include 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.


Nifedipine is often used to treat high blood pressure (hypertension), but it can also be useful in treating high altitude pulmonary oedema.

This medication decreases the narrowing of the artery that supplies blood to the lungs, helping to reduce chest tightness and ease breathing. It’s usually taken as a tablet at six- to eight-hour intervals.

Nifedipine can cause a sudden drop in blood pressure, so it’s important not to get up too quickly from a lying or sitting position if you take it.


This is a steroid which decreases brain and other swelling which can be a life saver if you have HACP or HACE. The dose is typically 4 mg twice a day for a few days starting with the ascent.

This prevents most of the symptoms of altitude illness from developing and essentially “buys time” especially at night when it may be problematic to descent.

WARNING: “Dexamethasone is a powerful drug and should be used cautiously and only on the advice of a physician. It is unwise to ascend while taking dexamethasone: unlike diamox this drug only masks the symptoms.”

Coca Leaves

If you are traveling to high altitudes in Central or South America, you could purchase coca leaves while you are there.

Coca is a stimulant that induces biochemical changes that enhance physical performance at high altitude, and locals throughout Central and South America chew on it or make tea to prevent altitude sickness.

Do however be aware that this is a substance which is illegal in the US. Even one cup of tea can result in a positive cocaine drug test.

Other Considerations

High altitudes put you at higher risk of exposure to the sun, of hypothermia, thrombophebitis (dangerous blood clots in leg veins) and retinopathy (eye damage).

Take full precautions to prevent sunburn and sunstroke, in particular, make sure you have appropriate eye protection – specialist sunglasses, snow goggles or equivalent. Snowblindness can occur even if it’s hazy.

If traveling to a high altitude destination it is absolutely essential to have taken out comprehensive travel medical insurance. Insurance which covers helicopter evacuation may save you a $100,000 bill.

Summary of Advice

As well as acclimatizing properly and taking prescription medication, you should also follow the advice outlined below.

  • Travel with a comprehensive first aid kit.
  • Travel with comprehensive travel insurance which covers emergency medical evacuation.
  • If you start to develop mild symptoms of altitude sickness, stay at your current altitude until your symptoms improve.
  • If your symptoms get worse, immediately descend from your current altitude.
  • Make sure everyone you’re travelling with has fully acclimatised before going any higher. Let someone know that you are beginning to feel unwell.
  • Gradual ascent is the most important preventive measure. If possible chose a trip with time for gradual acclimatisation built in. Ideally avoid flying directly to areas of high altitude. Consider using medication to aid acclimatisation if gradual ascent is not possible.
  • Get lots of rest. When ascending above 3,000m, try to have a rest day every three days. Gentle exercise only for the first 24 hrs.
  • Keep well hydrated by drinking plenty of fluids and maintain a high-calorie diet while at altitude.
  • Don’t smoke, drink alcohol or use medication such as tranquillisers and sleeping pills while you’re at altitude, as they could make any symptoms of altitude sickness worse. Speak to your GP if you’re unsure. 

Have you ever suffered from altitude sickness? Comment to tell us of your experience.

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