Health A-Z

Medical Content Created by the Faculty of the
Harvard Medical School

Altitude Sickness

Prevention

Gradual changes in altitude will help your body adapt to the low-oxygen environment and can reduce your chances of developing all forms of altitude sickness. People adapt at different rates, but there are four general guidelines for climbing above 10,000 feet that are practical for climbers to follow:

• Do not increase your altitude by more than 1,000 feet per night.

• Each time you increase your altitude by 3,000 feet, spend a second night at this elevation before going farther.

• Limit your physical exertion to reasonable levels during your first few days of ascent to altitude.

• Drink plenty of fluid during your altitude exposure.

If you develop early signs of altitude sickness, you can keep from getting worse if you immediately stop ascending or if you descend.

If you have experienced high-altitude illness in the past and are planning to again go to high altitude, you may want to discuss with your doctor the option of taking preventative medication. Mild symptoms of altitude adjustment (particularly sleep disruption from altered breathing patterns, but possibly other symptoms as well) can be limited by using acetazolamide (AK-Zol, Dazamide, Diamox, Storzolamide) or the corticosteroid medicine dexamethasone (Decadron, Dexone). Acetazolamide can cause frequent urination and a metallic taste in the mouth. These drugs do not prevent serious forms of altitude sickness.

If you previously have developed HAPE, you may receive the oral drug nifedipine (Procardia), the inhaled drug salmeterol (Serevent), or both medicines for a future rise to altitude. These medications may stabilize the blood-flow pattern in your lungs. Tadalafil (Cialis) and sildenafil (Viagra) are being studied as other possible preventive treatments for HAPE, and study results show some possible benefit. Use of either of these medicines for this purpose is still experimental.