Learn About Acute Mountain Sickness

What is the definition of Acute Mountain Sickness?

Acute mountain sickness is an illness that can affect mountain climbers, hikers, skiers, or travelers at high altitudes, usually above 8000 feet (2400 meters).

What are the alternative names for Acute Mountain Sickness?

High altitude cerebral edema; Altitude anoxia; Altitude sickness; Mountain sickness; High altitude pulmonary edema

What are the causes of Acute Mountain Sickness?

Acute mountain sickness is caused by reduced air pressure and lower oxygen levels at high altitudes.

The faster you climb to a high altitude, the more likely you will get acute mountain sickness.

The best way to prevent altitude illness is to ascend gradually. It is a good idea to spend a few days ascending to 9850 feet (3000 meters). Above this point ascend very slowly so that the elevation at which you sleep does not increase more than 990 feet to 1640 feet (300m to 500m) per night.

You are at higher risk for acute mountain sickness if:

  • You live at or near sea level and travel to a high altitude.
  • You have had the illness before.
  • You ascend quickly.
  • You have not acclimatized appropriately to the altitude.
  • Alcohol or other substances have interfered with acclimatization.
  • You have medical problems involving the heart, nervous system, or lungs.
  • If you have anemia
What are the symptoms of Acute Mountain Sickness?

Your symptoms will also depend on the speed of your climb and how hard you push (exert) yourself. Symptoms range from mild to life-threatening. They can affect the nervous system, lungs, muscles, and heart.

In most cases, symptoms are mild. Symptoms of mild to moderate acute mountain sickness may include:

  • Difficulty sleeping
  • Dizziness or lightheadedness
  • Fatigue
  • Headache
  • Loss of appetite
  • Nausea or vomiting
  • Rapid pulse (heart rate)
  • Shortness of breath with exertion

Symptoms that may occur with more severe acute mountain sickness include the following and may progress to high altitude pulmonary edema or high altitude cerebral edema:

  • Blue color to the skin (cyanosis)
  • Chest tightness or congestion
  • Confusion
  • Cough
  • Coughing up blood
  • Decreased consciousness or withdrawal from social interaction
  • Gray or pale complexion
  • Inability to walk in a straight line, or walk at all
  • Shortness of breath at rest
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What are the current treatments for Acute Mountain Sickness?

Early diagnosis is important. Acute mountain sickness is easier to treat in the early stages.

The main treatment for all forms of mountain sickness is to climb down (descend) to a lower altitude as rapidly and safely as possible. You should not continue climbing up if you develop symptoms.

Extra oxygen should be given, if available.

People with severe mountain sickness may need to be admitted to a hospital.

A medicine called acetazolamide (Diamox) may be given to help you breathe better. It can help reduce symptoms. This medicine can make you urinate more often. Make sure you drink plenty of fluids and avoid alcohol when taking this medicine. This medicine works best when taken before reaching a high altitude.

If you have fluid in your lungs (pulmonary edema), treatment may include:

  • Oxygen
  • A high blood pressure medicine called nifedipine
  • Beta agonist inhalers to open the airways
  • Breathing machine in severe cases
  • Medicine to increase blood flow to the lungs called phosphodiesterase inhibitor (such as sildenafil)

Dexamethasone (Decadron) may help reduce acute mountain sickness symptoms and swelling in the brain (cerebral edema).

Portable hyperbaric chambers allow hikers to simulate conditions at lower altitudes without actually moving from their location on the mountain. These devices are very helpful if bad weather or other factors make climbing down the mountain impossible.

Who are the top Acute Mountain Sickness Local Doctors?
Hematology | Hematology Oncology
Hematology | Hematology Oncology

City Of Hope Medical Foundation

209 Fair Oaks Ave, 
South Pasadena, CA 
 1.5 mi

Vinod Pullarkat is a Hematologist and a Hematologist Oncology provider in South Pasadena, California. Dr. Pullarkat and is rated as an Experienced provider by MediFind in the treatment of Acute Mountain Sickness. His top areas of expertise are Acute Myeloid Leukemia (AML), Acute Lymphoblastic Leukemia (ALL), Leukemia, Bone Marrow Transplant, and Bone Marrow Aspiration.

Hematology Oncology | Oncology | Hematology
Hematology Oncology | Oncology | Hematology
1505 Wilson Ter, Suite 340, 
Glendale, CA 
 4.7 mi
Offers Telehealth

Mihran Shirinian is a Hematologist Oncology specialist and an Oncologist in Glendale, California. Dr. Shirinian and is rated as a Distinguished provider by MediFind in the treatment of Acute Mountain Sickness. His top areas of expertise are Acute Erythroid Leukemia (AEL), Small Cell Lung Cancer (SCLC), Lung Adenocarcinoma, and Febrile Neutropenia.

 
 
 
 
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Hematology Oncology | Hematology | Oncology
Hematology Oncology | Hematology | Oncology

City Of Hope Medical Foundation

222 W Eulalia St, Suite 100b, 
Glendale, CA 
 6.3 mi
Offers Telehealth

Kalust Ucar is a Hematologist Oncology specialist and a Hematologist in Glendale, California. Dr. Ucar and is rated as an Experienced provider by MediFind in the treatment of Acute Mountain Sickness. His top areas of expertise are Breast Cancer, Familial Colorectal Cancer, Paget Disease of the Breast, and Colorectal Cancer.

What is the outlook (prognosis) for Acute Mountain Sickness?

Most cases are mild. Symptoms improve quickly when you climb down the mountain to a lower altitude.

Severe cases may result in death due to lung problems (pulmonary edema) or brain swelling (cerebral edema).

In remote locations, emergency evacuation may not be possible, or treatment may be delayed. This can have a negative effect on the outcome.

The outlook depends on how quickly the affected person can get to a lower altitude once symptoms begin. Some people are more prone to developing altitude-related sickness and may not respond as well as others.

What are the possible complications of Acute Mountain Sickness?

Complications may include:

  • Coma (unresponsiveness)
  • Fluid in the lungs (pulmonary edema)
  • Swelling of the brain (cerebral edema), which can lead to seizures, mental changes, or permanent damage to the nervous system
  • Death
When should I contact a medical professional for Acute Mountain Sickness?

Contact your provider if you have or had symptoms of acute mountain sickness, even if you felt better when you returned to a lower altitude.

Call 911 or the local emergency number if you or another climber have any of the following symptoms:

  • Altered level of alertness
  • Coughing up blood
  • Severe breathing problems

Climb down the mountain right away and as safely as possible.

How do I prevent Acute Mountain Sickness?

Keys to preventing acute mountain sickness include:

  • Climb the mountain gradually. Gradual ascent is the most important factor in preventing acute mountain sickness.
  • Stop for a day or two of rest for every 2000 feet (600 meters) of climb above 8000 feet (2400 meters).
  • Sleep at a lower altitude when possible.
  • Make sure that you have the ability to rapidly descend if needed.
  • Learn how to recognize early symptoms of mountain sickness.

If you are traveling above 9840 feet (3000 meters), you should carry enough oxygen for several days.

If you plan on climbing quickly, or climbing to a high altitude, ask your provider about medicines that may help prevent acute mountain sickness, such as acetazolamide or dexamethasone.

If you are at risk for a low red blood cell count (anemia), ask your provider if your planned trip is safe. Also ask if an iron supplement is right for you. Anemia lowers the amount of oxygen in your blood. This makes you more likely to have mountain sickness.

While climbing:

  • Do not drink alcohol
  • Drink plenty of fluids
  • Eat regular meals that are high in carbohydrates

You should avoid high altitudes if you have heart or lung disease.

What are the latest Acute Mountain Sickness Clinical Trials?
HighCycle Study: Effect of Acetazolamide on Acute Mountain Sickness in Women Compared to Men: A Randomized, Placebo-Controlled, Double-Blind Parallel Trial

Summary: Millions of people travel to high altitude for work or leisure activities and are exposed to reduced inspiratory oxygen partial pressure and hypoxemia that may lead to altitude illness, among which the most common form is acute mountain sickness (AMS). The main AMS symptoms are headache, malaise, weakness, and fatigue. Prospective studies have shown that 20-60% of newcomers at 2500-4000m develop A...

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HighCycle Study: Effect of High Altitude on Acute Mountain Sickness in Women Related to Their Menstrual Cycle Phase: A Prospective Cohort Study at 3600 m

Summary: Prospective cohort study investigating the menstrual cycle phase (MCP)-dependent incidence of acute mountain sickness (AMS) in women travelling to 3600 m.

Who are the sources who wrote this article ?

Published Date: November 02, 2023
Published By: Jesse Borke, MD, CPE, FAAEM, FACEP, Attending Physician at Kaiser Permanente, Orange County, CA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

What are the references for this article ?

Basnyat B, Paterson RD. Travel medicine. In: Auerbach PS, Cushing TA, Harris NS, eds. Auerbach's Wilderness Medicine. 7th ed. Philadelphia, PA: Elsevier; 2017:chap 79.

Cumpstey AF, Jackson AIR, Grocott MPW. Clinical care in extreme environments: physiology at high altitude and in space. In: Gropper MA, ed. Miller's Anesthesia. 9th ed. Philadelphia, PA: Elsevier; 2020:chap 74.

Harris NS. High-altitude medicine. In: Walls RM, ed. Rosen's Emergency Medicine: Concepts and Clinical Practice. 10th ed. Philadelphia, PA: Elsevier; 2023:chap 132.

Luks AM, Hackett PH. High altitude and preexisting medical conditions. In: Auerbach PS, Cushing TA, Harris NS, eds. Auerbach's Wilderness Medicine. 7th ed. Philadelphia, PA: Elsevier; 2017:chap 3.

Luks AM, Schoene RB, Swenson ER. High altitude. In: Broaddus VC, Ernst JD, King TE, et al, eds. Murray and Nadel's Textbook of Respiratory Medicine. 7th ed. Philadelphia, PA: Elsevier; 2022:chap 105.