Altitude Sickness: Symptoms and Prevention

Altitude sickness is a real, sometimes fatal risk that many holidaymakers overlook. Here are a few tips for overcoming altitude problems.

Acute mountain sickness (or "AMS"), also known as altitude sickness, is a real risk for any traveller heading to high altitude. Every year, thousands of people go up into the high mountains to ski, climb, hike or trek, but what many of them don't realise is that you don't necessarily need to climb above 3,000 m to risk suffering from altitude sickness!

What is acute mountain sickness?

Altitude sickness is linked to altitude. The higher you go, the lower the atmospheric pressure, leading to a drop in the amount of oxygen in the air around you. The body therefore finds it harder to get enough oxygen, and physical effort becomes increasingly difficult, which leads to a faster breathing and heart rate, and a general state of fatigue. Generally, the risk of suffering from altitude sickness appears from an altitude of 2,500 m and intensifies as altitude increases.

What are the symptoms of AMS?

The most common symptoms of acute mountain sickness are headaches (including migraines), nausea, fatigue or insomnia. Most of the time, these symptoms lessen or disappear after 3 to 4 days. In some cases, these symptoms can lead to more serious complications such as vomiting, behavioural changes, cerebral oedema, pulmonary oedema or cardiac problems. In such cases, you should descend to a lower altitude as soon as possible and, depending on the severity, follow medical treatment.

Who can be affected by altitude sickness?

Any traveller – even a healthy one – can suffer from altitude sickness. However, some people are more sensitive to it:

• Pregnant women, during the first and third trimesters of pregnancy;
• Young children, particularly above an altitude of 2,500 m;
• People suffering from cardiovascular diseases, blood or haematological disorders, chronic respiratory insufficiency, neurological problems or serious psychiatric disorders;
• Individuals requiring regular medical monitoring (insulin-dependent diabetes, kidney failure, retinopathy, etc.).

If in any doubt, get in touch with your doctor, tell them about your high-altitude holiday plans and ask for their advice.

How can you prevent altitude sickness?

If you're planning to travel to high-altitude regions such as the Alps, the Himalayan countries or the heights of the Andes, keep the following tips in mind:

• After a few days (3 to 4 days) at altitude, the body produces more red blood cells, allowing it to adapt to the altitude. So, on arrival, take the time to acclimatise and let your body get used to the altitude. If you then continue your ascent, don't climb more than 300m to 500m a day. These stages let you acclimatise gradually. Note that some people don't manage to adapt quickly enough. If that's your case, ask a doctor for advice.
• Make sure you stay well hydrated, and avoid alcohol and tobacco, as well as sedatives and sleeping pills.
• If you feel the symptoms of altitude sickness, go back down to a lower altitude.
• If the symptoms persist, seek medical advice.

Don't leave without travel insurance. It will guarantee you the essential support you need in the event of a medical problem.

First published: 03/2014 - Updated: 02/2020