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Altitude Sickness

What is altitude sickness?

Altitude sickness is also called acute mountain sickness. It is a problem that can occur if you travel to a high altitude (usually over 8000 feet above sea level). When you travel from a low elevation or sea level to a high altitude your body needs time to adjust (acclimate) to the altitude.

Symptoms of altitude sickness appear about 6 to 8 hours after arriving at a higher altitude. Symptoms may include:

  • headache, tiredness, dizziness, nausea, loss of appetite
  • shortness of breath and rapid heartbeat on exertion
  • insomnia or restless sleep.

Symptoms occur in about half of the people who suddenly go from sea level to 10,000 feet above sea level without giving their bodies a chance to get used to the altitude. The chance of having symptoms increases as the altitude gets higher.

What causes altitude sickness?

Altitude sickness is caused by the lower amount of oxygen in the air at higher altitudes. Your body has to work harder to get the oxygen it needs. Many people travel to mountainous areas (6,000 to 10,000 ft) and begin doing a lot of activity (such as hiking and skiing) before their bodies have had time to adjust.

How long will it last?

Most people with altitude sickness feel normal in 2 or 3 days.

In severe cases, when someone has made a sudden climb to over 10,000 ft and has overexerted himself, there can be life-threatening complications. These complications include pulmonary edema (lung failure) or cerebral edema (swelling of the brain).

How is it treated?

  • First aid for severe symptoms

    Quickly take your child to a lower altitude. Go down at least 2000 feet, and always go below 10,000 feet. If your child cannot walk, carry him or her in a sitting position. Give the child oxygen as soon as you can.

  • Rest for mild symptoms

    Symptoms usually go away after to 2 or 3 days of rest, fluids, and a light diet. Acetaminophen or ibuprofen can be given for the headache (aspirin may make it worse and is not recommended for children). The dizziness and headache can usually be improved by deliberately breathing faster and deeper to bring in more oxygen. Skiing, hiking, or any other type of exercise should be postponed. Once your child feels healthy again, he can gradually return to activities and higher elevation. Breathing from an oxygen tank can improve symptoms temporarily but is generally unnecessary when the symptoms are not severe.

How can altitude sickness be prevented?

  • Try to stage your mountain visit. Spend a few days at 5000 to 7000 feet before going to the high country.
  • Take it easy on the day of arrival. Some exercise (like short walks) is important, but take rest breaks. Gradually increase the amount of exercise during the second and third days.
  • Have your child drink a lot of fluids to prevent dehydration.
  • While mountain climbing, gain only 1000 feet per day.
  • If your child has had severe altitude sickness before, talk to your healthcare provider about taking Diamox tablets (a prescription medicine) for prevention in the future.

Newborns and mountain travel

Destinations and staying overnight in locations above 8,000 feet are a concern if you have a newborn. However, brief travel over mountain passes (10,000 to 11,000 feet) is safe. In general, travel to elevations above 8,000 feet are best postponed for the first month of life, unless you live at that elevation and your pregnancy took place there. If you are coming from sea level with a newborn, you should avoid mountain vacations above 8,000 feet for the first 1 or 2 months of life. Travel to the mountains shouldn't cause any problems if the destination is less than 8,000 feet.

When should I call my child's healthcare provider?


  • Your child becomes confused or staggers when he walks.
  • Breathing becomes labored.
  • A headache becomes severe.
  • Vomiting has occurred 3 or more times.
  • Your child starts acting very sick.

Call during office hours if:

  • The symptoms last more than 3 days.
  • You have other questions or concerns.
Pediatric Advisor 2012.2 published by RelayHealth.
Last modified: 2009-06-18
Last reviewed: 2011-06-06
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