It doesn’t take much for altitude sickness to set in. Anyone with experience in the Colorado Rockies is familiar with the headache, nausea and fatigue symptomatic of Altitude Sickness, itself a type of Acute Mountain Sickness. While most cases subside, staying at altitude or going higher can cause even serious problems, like High Altitude Pulmonary Edema or Cerebral Edema, which can cause death. You may be wondering how to prevent altitude? Can it even be done?
Thankfully, with a little pre-planning and preparation it is easy to prevent altitude sickness in most cases. By making time for acclimation, you can significantly reduce your odds of falling ill, increasing your chances of reaching the summit!
What Causes Altitude Sickness?
Altitude Sickness results from a rapid reduction in the amount of oxygen available to breathe. While oxygen still makes up around 20% of the air, the air is thinner, leaving a lower oxygen pressure in your lungs. This makes gas transport more difficult, lowering oxygen levels in the blood and causing headaches, nausea, dizziness and fatigue.
While AS can be annoying or even debilitating, it is generally not life-threatening unless you remain at a high altitude with AS for a significant period of time. In such a situation, it can progress to a more serious version of AMS like high altitude pulmonary edema, in which blood clots form in the lungs. This and other conditions can be serious and life-threatening.
Fear not: AS only affects about 20% of those who move past 8,000 feet, and 40% of those above 10,000 feet. Yet when you consider those who take time to acclimate, these rates are far lower. Here’s how to prevent altitude sickness.
Acclimation is Key: Take Time to Ascend
Whenever you’ll be spending significant time above 8,000 to 10,000 feet, you should plan to make time for acclimation. By spending an extra night between 5,000 and 8,000 feet, you give your body time to adjust to higher altitude, preventing AS. If you’re from a higher-altitude area, like Denver or Salt Lake City, you can probably skip this first day, and proceed to 8,000 feet.
The Wilderness Medicine Society recommends climbers take a night to acclimate for every 1,000 feet gained above 10,000 feet. For every 3,000 feet gained, they should take an additional rest day. As an example, if climbing a 14,500 foot mountain you might follow this example altitude schedule:
- 1st Day: Drive to camp at trailhead at 7,500 feet and sleep
- 2nd Day: Hike up to Camp I at 10,000 feet and sleep
- 3rd Day: Hike up to Camp II at 11,000 feet and sleep
- 4th Day: Climb 3,500 feet to summit at 14,500 feet. Descend back to car.
Climbers refer to this prep as “Climbing High and Sleeping Low.” You can climb more than 1,000 feet in a day, so long as you return lower to sleep. This allows for larger pushes on summit day, so long as you make it back to lower elevation.
Medication Can Help But is No Guarantee
There are three different medications that can help treat or prevent the symptoms of Altitude Sickness. However it’s important to remember that these only treat symptoms – they are no replacement for proper acclimation. Relying on medication alone may put you at a serious risk of developing life-threatening conditions. However, used with a good ascending schedule, they can give you extra protection against AS symptoms.
- Over-the-Counter Painkiller: When experiencing headache or body aches, ibuprofen or tylenol can help reduce the pain. Don’t take more than the standard dose, and take it with food like a bar or trail mix.
- Acetazolamide (Brand name Diamox) works by increasing your breathing rate, allowing you to metabolize more oxygen. This takes time to take effect, so you should start taking 125mg twice a day a full day before you reach higher altitudes. Diamox requires a prescription: setup an appointment with your doctor or at a Walk-in clinic, and follow all the doctor’s instructions.
- Dexamethasone is a steroid which helps prevent and treat the symptoms of AS. However unlike Acetazolamide, stopping taking it at altitude can cause a rebound and more damage than going without it. It also requires a prescription, and has more significant risks than Acetazolamide alone, thought they can be taken together. Follow all your doctor’s instructions exactly.
Don't Fall for Gimmicks: There Are No Shortcuts
Acclimation takes time… and people are eager to find quicker ways to avoid altitude sickness. Unfortunately that’s led to a great deal of gimmicks and fads when it comes to preventing AS. Oxygen canisters are widespread in Colorado and California, especially at outfitting and outdoor recreation stores. However there’s no real evidence they help prevent or treat AS. To put them in context, each can contains less than a liter of oxygen, but when treating a patient with oxygen, EMTs use 15 liters per minute. There is simply too little oxygen in those cans to make a difference – especially considering their weight.
Treating AS When it Still Strikes
Now you know how to prevent altitude sickness… However, even with proper acclimation, medication and knowledge, altitude sickness can still strike. When this happens, it’s important to know your options. If you have painkillers, you can try to treat mild symptoms. Regardless, the only way to cure altitude sickness is to descend to a lower elevation. If you continue to ascend or spend significant time, you may develop a life-threatening condition. The mountain will be there tomorrow – it’s better to retreat to fight another day.
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About the Author: Alex Derr
Alex Derr is a mountaineer and blogger based in Denver Colorado. He is working to climb Colorado’s highest 100 peaks, and the 20 tallest peaks in California. He created The Next Summit to share advice, stories, history & reflections from the Colorado Rockies & Sierra Nevada. When not climbing, he is managing the Communications strategy at Visible Network Labs.