Healthdirect Free Australian health advice you can count on.

Medical problem? Call 1800 022 222. If you need urgent medical help, call triple zero immediately

healthdirect Australia is a free service where you can talk to a nurse or doctor who can help you know what to do.

Two hikers walking at high altitude.

Two hikers walking at high altitude.
beginning of content

Altitude sickness

3-minute read

What is altitude sickness?

Altitude sickness, also known as mountain sickness, can happen if you travel to a high altitude.

Altitude sickness can affect anybody — being young or physically fit does not decrease the risk.

Whether or not you get altitude sickness could depend on:

  • your height above sea level
  • the time you took to make the ascent
  • whether or not you have any problems affecting your heart and lungs

Altitude sickness can be fatal if not treated.

What are the symptoms of altitude sickness?

If you have altitude sickness, you are likely to feel dizzy and weak, you might also have a headache and feel nauseous. It can feel like a hangover.

Altitude sickness can affect your lungs, in which case it is sometimes known as high altitude pulmonary oedema or HAPE. People with HAPE can feel short of breath and have a cough and a racing heart. In extreme cases, their lips turn blue.

Altitude sickness can also cause your brain to swell with fluid, which is sometimes known as high altitude cerebral oedema or HACE. People with HACE can feel confused and irritable and behave in an erratic way.

Altitude sickness can be worse at night and can last for days, even if you stay at the same altitude.

CHECK YOUR SYMPTOMS — Use the Symptom Checker and find out if you need to seek medical help.

What causes altitude sickness?

Altitude sickness is caused by low oxygen levels in the air at altitudes above about 2,500 metres. It occurs when the body has not had time to adjust to less oxygen.

How is altitude sickness treated?

If you have altitude sickness, you should stay at the same altitude or go lower until the symptoms disappear. Rest, fluids and painkillers are likely to improve the symptoms. Do not continue to climb higher.

It is best not to drink alcohol or take sedatives or sleeping pills because they interfere with the body's adaptation to high altitude.

If you have signs of altitude sickness affecting your lungs or your brain, this is a medical emergency. You need help to descend as soon as possible. Breathing oxygen from a tank can help.

FIND A HEALTH SERVICE — The Service Finder can help you find doctors, pharmacies, hospitals and other health services.

ASK YOUR DOCTOR — Preparing for an appointment? Use the Question Builder for general tips on what to ask your GP or specialist.

Can altitude sickness be prevented?

If you're planning to travel to a high altitude, consider talking to your doctor about drugs that can help with acclimatisation, particularly if you have had altitude sickness before.

You can reduce the chance of getting altitude sickness by:

  • avoiding a rapid ascent from sea level — don't go above about 2,500 metres for the first night's sleep
  • once you get above 3,000 metres, ascending by no more than 500 metres per day
  • spending the night below the day's highest altitude
  • avoiding strenuous exercise before your body has had time to adjust to the lower oxygen levels
  • avoiding alcohol at high altitude
  • resting for the 48 hours after arriving at a place of high altitude

If you have a medical problem that affects your lungs, heart or circulation, you are at increased risk of getting altitude sickness.

Learn more here about the development and quality assurance of healthdirect content.

Last reviewed: July 2020


Back To Top

Need more information?

These trusted information partners have more on this topic.

Top results

Altitude sickness - myDr.com.au

Most people can ascend to a level of 2000 metres in one day without getting sick. Acute mountain sickness is the mildest form of altitude sickness, but can develop into more dangerous forms of altitude sickness.

Read more on myDr website

Altitude sickness - Better Health Channel

Being young and fit doesn't reduce your risk of altitude sickness.

Read more on Better Health Channel website

Headache Types - Headache Australia

Review over 20 different headache types in this directory.

Read more on Migraine and Headache Australia website

Motion sickness - myDr.com.au

Many people eventually grow out of motion sickness (travel sickness), but for those who don’t there are treatments available and things you can do to help prevent it and ease the symptoms.

Read more on myDr website

Exercising during pregnancy

Doing regular moderate physical activity has health benefits during pregnancy and also helps to prepare the body for childbirth. Read about getting fit during pregnancy.

Read more on Pregnancy, Birth & Baby website

Travel medical kit checklist - myDr.com.au

Stay safe when you are travelling with this checklist of handy health supplies and find a list of what to take in your travel medical kit on myDr.com.au.

Read more on myDr website

Healthdirect 24hr 7 days a week hotline

24 hour health advice you can count on

1800 022 222

Government Accredited with over 140 information partners

We are a government-funded service, providing quality, approved health information and advice

Australian Government, health department logo ACT Government logo New South Wales government, health department logo Northen Territory Government logo Government of South Australia, health department logo Tasmanian government logo Government of Western Australia, health department logo