Altitude Sickness

Altitude Sickness Risk Calculator

Altitude sickness, or acute mountain sickness, is caused by travelling to a high altitude at a faster pace than your body can adapt to it.
At high altitudes of 2,500 meters above sea-level and above, air pressure is only half of what it is at sea-level, leading to a reduction in the amount of oxygen available. It can be a dangerous condition, so it is very important to recognise and react to symptoms at an early stage to avoid medical emergencies. Age, sex or physical fitness have no bearing on your likelihood of getting altitude sickness.

Our altitude calculator works out the altitude of every location on your travel itinerary and formulates the information into a simple graphic format so you can understand your altitude sickness risk. This will help you understand whether you need to slow down your ascent to help lower your risk.

You can bring your results with you to your travel consultation to discuss with a travel nurse.


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What is Altitude Sickness?

Altitude sickness is unpleasant and if not taken seriously, can turn into something serious and life-threatening.

Oxygen levels in high elevation are lower than that at sea-level. If travellers rapidly ascend to these high-altitudes, the body sometimes doesn’t have sufficient time to acclimatise, leading to altitude sickness. As a result, breathing becomes difficult because you aren’t able to take in as much oxygen. Just because you haven’t had it before doesn’t mean you won’t develop it on another trip. Altitude sickness is highly unpredictable.

What are the symptoms of Altitude Sickness?

Symptoms of altitude usually appear within 24 hours of reaching 2,500m above sea-level and higher.

Mild symptoms can be quite similar to those of a bad hangover, such as:

  • headache
  • nausea and vomiting
  • dizziness
  • tiredness
  • loss of appetite
  • shortness of breath

Symptoms usually worsen at night. Altitude sickness can progress rapidly to more serious forms affecting either the lungs or the brain. Pulmonary or cerebral edema can develop (a build-up of tissue fluid in the lungs or the brain) which if left untreated can be fatal.

Is there any medication available to prevent/ treat Altitude Sickness?

Many people who are travelling to high altitudes use medication called Diamox (acetazolamide), which can help speed up the body’s acclimatisation.

This can be used either for prevention or for treatment. We will be able to advise you on the best course of action for your trip during a travel consultation.

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Need more information?

Book a travel consultation with one of our specialist travel nurses.

During your appointment, you can discuss all your travel plans and we can advise you on how to reduce your risk of travel-related DVT, as well as go through any travel vaccinations and travel medications you should consider. This personalised service will take into account all your travel plans and we’ll create a bespoke health plan to keep you healthy throughout your travels.

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High altitude destinations include popular locations that fall on the Andes Mountain Range in South America, such as Machu Picchu or La Paz in Bolivia. Other popular destinations include Tibet, Nepal, Bhutan or Tanzania (Mt Kilimanjaro).

Ascending slowly is the key to preventing altitude sickness, that includes flying directly to areas of high altitude. Ideally, choosing a longer trek with a slower ascent over more days will reduce your risk considerably. Ensure you maintain good hydration and nutrition throughout your ascent.

Many people who are doing serious trekking may choose to take a pulse oximeter with them. This is a small portable device that allows the monitoring of oxygen levels in the bloodstream.

If you think you have altitude sickness it is important you stop and rest where you are. Don’t climb to a higher altitude, you need to acclimatise for at least 24 hours. If symptoms worsen, you will need to seek medical assistance.