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Altitude sickness

Related Terms
  • Acclimation, altitude, altitude sickness, AMS, cerebral edema, coma, CPAP, edema, Gamow bag, HACE, HAPE, HARH, high altitude sickness, hyperbaric chamber, hyperbaric therapy, mountain climbing, mountain sickness, ophthalmoscopy, oxygen, oxygen saturation, pulmonary edema, pulse oximetry, respiratory failure, retina, supplemental oxygen.

  • Altitude sickness, also called mountain sickness, is an illness that occurs when the body is unable to adjust to high elevations. Symptoms of mountain sickness range from a mild headache and fatigue to a life-threatening build-up of fluid in the lungs or brain.
  • People may be exposed to high altitudes when they go rock climbing, mountain climbing, or skiing. At higher altitudes, there is less oxygen in the air. If a patient does not allow the body sufficient time to adjust to changes in altitude, the body does not receive enough oxygen, and symptoms of mountain sickness develop. Individuals who live at high elevations generally do not experience mountain sickness because their bodies are adjusted to the altitude.
  • Most patients will experience a full recovery if they start to descend to lower elevations shortly after symptoms of mountain sickness develop.
  • There are four forms of mountain sickness: acute mountain sickness, high altitude pulmonary edema, high altitude cerebral edema, and high altitude retinal hemorrhage.
  • Acute mountain sickness (AMS) is the mildest and most common type of mountain sickness. Mountain sickness typically develops when patients travel to elevations higher than 8,000 feet above sea level at a rate that is faster than 1,000 feet per day. Researchers estimate that nearly 50% of people who start at or near sea level and climb to 14,000 feet without scheduling rest time develop this condition.
  • If patients with AMS continue to climb or travel to higher elevations despite their symptoms, their condition may progress to a more severe form, such as high altitude pulmonary edema (HAPE). This condition occurs when fluid builds up in the lungs, making breathing difficult. Additional treatments, such as supplemental oxygen, may help reduce symptoms. If left untreated, the condition can lead to respiratory failure and death. HAPE is the number one cause of death from mountain sickness.
  • AMS may also develop into a severe condition called high altitude cerebral edema (HACE). This condition occurs when fluids builds up inside the brain, causing the brain to swell. As the brain swells, the person begins to feel confused and coordination becomes impaired. Some patients may experience permanent mental impairment and loss of coordination. The severity of these impairments varies among patients. If HACE is not treated, patients will develop a coma and die. More than 50% of HACE patients who develop a coma die.
  • Some patients with AMS may develop high altitude retinal hemorrhage (HARH). This condition occurs when there is bleeding in the eye(s). Bleeding may not be visible to the patient. A common symptom is blurred vision. Left untreated, HARH may lead to permanent eye damage or vision loss.
  • Patients with mountain sickness may develop HAPE, HACE, or HARH separately, or they may develop more than one of these conditions at the same time.

Integrative therapies
  • Note: Acute mountain sickness (AMS) may develop into life-threatening conditions. Individuals with symptoms of mountain sickness should seek proper medical attention immediately. Individuals who are planning on climbing high altitude mountains should bring proper medical equipment. Patients who experience symptoms of more serious forms of mountain sickness, including high altitude pulmonary edema (HAPE), high altitude cerebral edema (HACE), or high altitude retinal hemorrhage (HARH), should begin to descend to lower elevations immediately and seek proper medical attention.
  • Good scientific evidence:
  • Yoga: Yoga uses controlled breathing patterns to increase respiratory efficiency. Clinical study has found that at high altitude, subjects practicing yoga had improved oxygen use and ventilation and reduced changes in their blood that resembled Himalayan natives. More research is needed to further clarify the use of yoga in treatment of altitude sickness.
  • Yoga is generally considered to be safe in healthy individuals when practiced appropriately. Avoid some inverted poses with disc disease of the spine, fragile or atherosclerotic neck arteries, risk for blood clots, extremely high or low blood pressure, glaucoma, detachment of the retina, ear problems, severe osteoporosis, or cervical spondylitis. Certain yoga breathing techniques should be avoided in people with heart or lung disease. Use cautiously with a history of psychotic disorders. Yoga techniques are believed to be safe during pregnancy and breastfeeding when practiced under the guidance of expert instruction (the popular Lamaze techniques are based on yogic breathing). However, poses that put pressure on the uterus, such as abdominal twists, should be avoided in pregnancy.
  • Unclear or conflicting scientific evidence:
  • Ginkgo: Ginkgo biloba has been used to treat medical conditions for thousands of years. Today, it is one of the top selling herbs in the United States. A small amount of poorly designed research reports benefits of Ginkgo biloba for the treatment of altitude sickness. Additional study is needed before a recommendation can be made.
  • Avoid if allergic or hypersensitive to members of the Ginkgoaceaefamily. If allergic to mango rind, sumac, poison ivy or oak, or cashews, then allergy to Ginkgo biloba is possible. Avoid with blood-thinners (such as aspirin or warfarin) due to an increased risk of bleeding. Ginkgo biloba should be stopped two weeks before and immediately after surgical procedures. Ginkgo biloba seeds are dangerous and should be avoided. Skin irritation and itching may also occur due to Ginkgo biloba allergies. Do not use Ginkgo biloba in supplemental doses if pregnant or breastfeeding.
  • Vitamin E: Vitamin E may offer some benefits in exposure to high altitude. Antioxidant supplementation (vitamin E with beta carotene, vitamin C, selenium, and zinc) may improve ventilatory threshold at high altitudes; however, antioxidants may not reduce inflammation after exercise at high altitudes. More research is needed before conclusions can be drawn on the effectiveness of Vitamin E for altitude sickness.
  • Avoid if allergic or hypersensitive to vitamin E. Avoid with retinitis pigmentosa (loss of peripheral vision). Use cautiously with bleeding disorders or if taking blood thinners. Avoid above the recommended daily level in pregnant women and breastfeeding women.
  • Fair negative scientific evidence:
  • Arginine: Based on early research, L-arginine supplementation has not been shown to be an effective therapy in prevention of altitude sickness.
  • Avoid if allergic to arginine, or with a history of stroke, or liver or kidney disease. Avoid if pregnant or breastfeeding. Use caution if taking blood-thinning drugs (like warfarin or Coumadin®) or blood pressure drugs or herbs or supplements with similar effects. Blood potassium levels should be monitored. L-arginine may worsen symptoms of sickle cell disease. Caution is advised in patients taking prescription drugs to control blood sugar levels.
  • Traditional or theoretical uses lacking sufficient evidence:
  • Reishi mushroom: Reishi mushroom (Ganoderma lucidum), also known as Ling Zhi in China, grows wild on decaying logs and tree stumps. It has been suggested that reishi mushroom may help with treatment and prevention of altitude sickness. However, studies have not been performed to test the safety and effectiveness of this therapy.
  • Avoid if allergic or hypersensitive to any constituents of Ganoderma lucidum or any member of its family. Use cautiously with diabetes, blood disorders (including hemophilia), low blood pressure, or ulcers. Avoid if pregnant or breastfeeding.
  • Rhodiola: Rhodiola has been used traditionally in Eastern Europe and Asia for increasing resistance to physical stress, enhancing work performance, reducing fatigue, and preventing altitude sickness. Rhodiola has been suggested to protect against hypoxia (reduction of oxygen supply in the body), however there is a lack of evidence for this use in available human study. Well-designed clinical studies are required in this area.
  • Avoid if allergic or sensitive to Rhodiola. Use cautiously in people with diabetes, cardiovascular disease, or neurological or psychiatric disorders. Rhodiola is not recommended for use during pregnancy or breastfeeding.
  • Selenium: Selenium is a mineral found in soil, water, and some foods. Although selenium has been suggested as a possible treatment for altitude sickness, studies are lacking. Research is needed in order to determine if this treatment is safe and effective in humans.
  • Avoid if allergic or sensitive to products containing selenium. Avoid with a history of non-melanoma skin cancer. Selenium is generally regarded as safe for pregnant or breastfeeding women. However, animal research reports that large doses of selenium may lead to birth defects.

Author information
  • This information has been edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (

Copyright © 2011 Natural Standard (

The information in this monograph is intended for informational purposes only, and is meant to help users better understand health concerns. Information is based on review of scientific research data, historical practice patterns, and clinical experience. This information should not be interpreted as specific medical advice. Users should consult with a qualified healthcare provider for specific questions regarding therapies, diagnosis and/or health conditions, prior to making therapeutic decisions.

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