What is altitude sickness?

Altitude sickness is a condition which can affect travellers visiting regions at an altitude of over 2400m. It occurs when your are exposed to a lower percentage of oxygen in the air than you’re used to.

Symptoms are often mild and usually resolve without treatment within a few days. However, in severe cases altitude sickness can cause serious complications and it can be fatal. It is important that you know how to spot symptoms and that you understand when to rest and take time to adjust to the change in altitude.

Which symptoms does it cause?

The symptoms of altitude sickness are sometimes compared to those of a hangover.

  • Symptoms can include:
  • Headache
  • Feeling or being sick
  • Loss of appetite
  • Feeling dizzy
  • Tiredness
  • Shortness of breath

Some travellers find that the symptoms are more pronounced in the evening and at night.

Altitude sickness is not an indication of poor fitness and it is difficult to predict whether you will have symptoms or not.

What do I do if I have altitude sickness?

If you experience symptoms of altitude sickness, stay at the altitude you’re currently at for at least 1 - 2 days. Avoid strenuous exercise and make sure you are drinking enough water to stay hydrated.

It is best to avoid alcohol and smoking as both may cause your symptoms to worsen.

You can use over the counter painkillers such as paracetamol or ibuprofen to treat your headache if required.

It is important that you let any fellow travellers know how you feel - don’t try and keep up with them if you’re not well.

Don’t go to a higher altitude until you have fully recovered. If your symptoms last for more than a day, go down to a lower altitude (at least 500m lower). If your symptoms don’t go away, see a doctor. You may be able to use a medicine called acetazolamide, which is usually used to prevent altitude sickness to speed up recovery.

If your symptoms have gone away altogether after resting for a couple of days, you can think about continuing going up again. Make sure you take it slowly and be careful to look out for any symptoms returning.

What are the risks and complications of altitude sickness?

It is extremely important that you don’t ignore your symptoms if you have altitude sickness. A further increase in altitude when you’re already experiencing symptoms will not just cause you to feel worse but can also be very dangerous.

Seek medical help without delay if you or a fellow traveller experience any of the following symptoms:

  • Nausea and vomiting
  • Confusion and hallucinations
  • Weakness
  • Blue tinge to the skin
  • Difficulty breathing even at rest
  • Chest tightness
  • A cough (may bring up liquid)
  • Coordination problems

These symptoms can indicate that you are suffering from a swelling of the brain or fluid in your lungs caused by altitude sickness.

It is vital that you move to a lower altitude immediately, use bottled oxygen if you can, and see a doctor without delay.

If anyone you are travelling with is suffering from these symptoms, make sure they do not travel further but ensure they seek medical help. It is not usual for travellers who suffer from these complications to misjudge their condition. If these conditions are left untreated they are likely to be fatal.

How can I prevent altitude sickness?

The most effective way to prevent altitude sickness is to increase the altitude you’re at gradually. It is best to get used to a high altitude for 1 - 2 days before climbing to an altitude of more than 3000m.

Once above 3000m you shouldn’t increase the altitude you’re at by more than 300 - 500m a day. You should also plan in rest days between every 600 - 900m that you go up.

Make sure you drink enough water and stay hydrated.

You may be able to use a preventative altitude sickness treatment. Acetazolamide (also sold under the brand name Diamox) can help you adjust to high altitude quicker and reduces the risk of symptoms or the severity of any symptoms you experience.

However, taking a treatment doesn’t mean that you can ignore symptoms. You still need to introduce higher altitudes gradually and take care to rest if you develop the condition.