What Is Acute Mountain Sickness?

    Hikers, skiers and adventurers who travel to high altitudes can sometimes develop acute mountain sickness, also referred to as altitude sickness or high altitude pulmonary edema. It typically occurs at about 8,000 feet, or 2,400 meters above sea level. Dizziness, nausea, headaches, and shortness of breath are a few symptoms of this condition. Most instances of altitude sickness are mild and heal quickly. In rare cases, however, altitude sickness can become severe, causing complications with the lungs or brain.

    What Causes Acute Mountain Sickness?

    Higher altitudes contain lower oxygen and decreased air pressure. When you travel in a plane, drive or hike up a mountain, or go skiing, your body may not have enough time to adjust, resulting in altitude sickness. Generally, your level of exertion plays a role. Pushing yourself to quickly hike up a mountain, for example, may cause acute mountain sickness.

    Who Is at Risk for Acute Mountain Sickness?

    Your risk of experiencing acute mountain sickness is greater if you live by or near the sea and are unaccustomed to higher altitudes. Other risk factors include:

    • quick movement to high altitudes
    • physical exertion while traveling to a higher altitude
    • traveling to extreme heights (for example, anything above 14,000 feet)
    • a low red blood cell count due to anemia
    • heart or lung disease
    • past bouts of acute mountain sickness

    What are the Symptoms of Acute Mountain Sickness?

    The symptoms of altitude sickness generally appear within hours of moving to higher altitudes, and vary depending on the severity of your condition. If you have a mild case, you may experience:

    • dizziness
    • headache
    • muscle aches
    • insomnia
    • nausea and vomiting
    • irritability
    • loss of appetite
    • swelling of the hands, feet, and face
    • rapid heartbeat
    • shortness of breath with physical exertion

    Severe cases of acute mountain sickness can cause more intense symptoms, affecting your heart, lungs, muscles, and nervous system. For example, you may experience confusion as a result of brain swelling. Or you may suffer from shortness of breath caused by fluid in the lungs.

    Symptoms of severe altitude sickness may include:

    • coughing
    • chest congestion
    • pale complexion and skin discoloration
    • inability to walk or lack of balance
    • social withdrawal

    Seek medical attention as soon as possible. The condition is much easier to treat if you address it before it progresses.

    How Is Acute Mountain Sickness Diagnosed?

    Your doctor will ask you to describe your symptoms, activities, and recent travels. During the exam, your doctor will most likely use a stethoscope to listen for fluid in your lungs. To pinpoint the severity of the condition, your physician may also order a chest X-ray.

    How is Acute Mountain Sickness Treated?

    Treatment for acute mountain sickness varies depending on its severity. You might be able to avoid complications by simply returning to a lower altitude. Hospitlization is required if your doctor determines that there is brain swelling or fluid in your lungs. Oxygen may be administered if you are experiencing breathing issues.

    Medications

    Medications for altitude sickness include:

    • acetazolamide to correct breathing problems
    • blood pressure medicine
    • lung inhalers
    • dexamethasone to decrease brain swelling
    • aspirin for headache relief

    Other Treatments

    Some basic interventions may be able to treat milder conditions, including:

    • returning to a lower altitude
    • reducing your activity level
    • resting for at least a day before moving to a higher altitude
    • hydrating with water

    Outlook

    Most people are able to recover from a mild case of acute mountain sickness quickly after returning to lower altitudes. Symptoms typically subside within hours, but may last up to two days. However, if your condition is severe and there is little access to treatment, complications can lead to swelling in the brain and lungs, resulting in coma or death. Therefore, it is essential to plan ahead when traveling to high altitude locations.

    Prevention

    Here are important preventive steps to take before traveling to high altitudes:

    • Get a physical to make sure you have no serious health issues.
    • Review the symptoms of mountain sickness so you can recognize and treat them quickly if they occur.
    • If traveling to extreme altitudes (higher than 10,000 feet, for example), ask your doctor about acetazolamide, a medication that can ease your body’s adjustment to high altitudes. Taking it the day before you climb and on the first day or two can lessen your symptoms.

    When climbing to higher altitudes, prevent acute mountain sickness by doing the following:

    • Climb gradually, if possible. Instead of moving from zero to 8,000 feet all in one day, rest for a day after every 2,000 feet.
    • Return to sleep in lower altitudes to give your body a break.
    • Carry oxygen with you when climbing above 9,000 to 10,000 feet.
    • Drink plenty of fluids.
    • Avoid alcoholic beverages.
    • Eat frequent, high-carbohydrate meals.
    • Avoid unnecessary physical exertion, particularly in the initial climb.

    Avoid climbing to high altitudes if you have any of the following conditions or if these situations apply to you:

    • Anemia. Having anemia causes a low red blood cell count, which reduces the amount of oxygen in your blood. Ask your doctor about taking an iron supplement, and treat the issue before going to high altitudes.
    • Heart and lung disease. If you have either heart or lung disease, the combination of high altitudes and low oxygen can be difficult to endure.
    • You take drugs that lower your breathing rate. If you take medications like sleeping pills, narcotic pain relievers and tranquilizers, check with your doctor before climbing to high altitudes.
    • You felt ill in the past during previous climbs.