Altitude sickness is one of the greatest risks of trekking in Nepal and needs to be properly understood. We attempt to provide you with the information you need here, but it is advised that you also do your own research on the topic, to ensure you are fully informed. All of our guides are aware of the risks, signs and symptoms of altitude sickness, as well as the management of the condition.
Altitude sickness is a dangerous condition, but fortunately most cases of altitude sickness are mild. However, in extreme cases it can be life-threatening and result in death. This is not to scare you or deter you joining us on a trek in Nepal! To put it into context, each year, on average, four people die trekking in Nepal due to altitude sickness. This is a tiny percentage of the tens of thousands who visit Nepal to trek each year. So while it is a risk that must be taken into consideration, the chances of a fatality are extremely low. And if you come armed with a little knowledge of altitude sickness, and what symptoms to look out for, you’ll feel a lot safer while trekking in Nepal.
In short, altitude sickness comprises a group of physically distressing symptoms that can occur when a person travels from an area of lower altitude to higher altitude in a short period of time. It is the result of the body struggling to adjust to lower oxygen pressure at higher altitudes. Not everyone will feel the effects of altitude. Some people are more susceptible than others, and it cannot be predicted who will experience altitude sickness. Even if you have travelled to higher altitude with no problems before, you may experience altitude sickness on your next ascent to altitude.
The Symptoms of Altitude Sickness
The progression of symptoms is usually gradual, meaning that you generally have time to react appropriately. You can diagnose altitude sickness yourself, and it can be easily treated if you are cautious and react when necessary. Symptoms usually appear within just a few hours of arriving at altitude and can include:
Nausea/loss of appetite
Shortness of breath
An inability to exercise
Swelling (oedema) of the hands and face
The above may also simply be normal symptoms of acclimatisation, and you can continue to trek while experiencing mild levels of these symptoms, however the key to managing and keeping healthy is just to be aware of whether or not the symptoms are worsening. The most effective treatment is to descend to a lower altitude to acclimatise before attempting to ascend again, but the severity of your symptoms will determine how quickly you need to do this.
Some people find that certain medications (such as Diamox), or local remedies (such as garlic soup) can help with acclimatisation and prevent the onset, or alleviate the symptoms, of altitude sickness. Please check with your doctor before trekking as to whether or not you can safely take this medication. It is readily available over the counter in Nepal.
The majority of people trekking at high altitude will experience some form of altitude sickness, and we wish to reiterate that the most important thing is to notice an increasing degree of any of the symptoms listed above.
More Information on Altitude Sickness
Our list above offers the more obvious symptoms. If you’re interested to learn more there are some great sites that provide in-depth information about general altitude sickness as well as ‘acute mountain sickness.’ Below are links to some of the more helpful online resources we have found. We also recommend reading the Lonely Planet book Trekking in the Nepal Himalaya. This book is fantastic and a must read for anyone planning to trek in Nepal - it also includes invaluable information on altitude sickness.
When you reach Kathmandu, if you want to learn more about altitude sickness before the trek starts, you can also visit the Himalayan Rescue Association office. The HRA also has an outpost in the village of Manang where we will spend a day for acclimatisation on the Annapurna Circuit route before ascending to Thorong La, as well as Periche and Everest Base Camp in the Everest Region.
Recommended online reading