Altitude Sickness

What is altitude sickness?

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

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

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

Symptoms occur in 50% of nonacclimated people who go abruptly from sea level to 10,000 feet above sea level. The likelihood of 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. Descend at least 2000 feet, and always go below 10,000 feet elevation. If your child cannot walk, carry him or her in a sitting position. Give the child oxygen as soon as it becomes available.

  • Rest for mild symptoms

    Symptoms usually go away after to 2 or 3 days of rest, fluids, and a light diet. Acetaminophen can be given for the headache (aspirin may make it worse). 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, activity should be resumed gradually. 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 journeying 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.
  • Avoid dehydration by drinking a lot of fluids.
  • While mountain climbing, gain only 1000 feet per day.
  • If your child has experienced severe altitude sickness before, talk to your health care provider about taking Diamox tablets (a prescription medicine) for prevention in the future.

When should I call my child's health care provider?

Call IMMEDIATELY if:

  • Your child becomes confused.
  • Breathing becomes labored or fast.
  • 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.


Written by B.D. Schmitt, M.D., author of "Your Child's Health," Bantam Books.
Published originally by McKesson Health Solutions LLC.
Adapted by Premier Care Pediatrics, PA.
This content is reviewed periodically and is subject to change as new health information becomes available. The information is intended to inform and educate and is not a replacement for medical evaluation, advice, diagnosis or treatment by a healthcare professional.