Updated November 20, 2018.
If you’ve ever hiked Machu Picchu, climbed Kilimanjaro, or even skied some particularly intense slopes, you might be familiar with altitude sickness. It’s a common ailment — studies show that 25 percent of people show signs of it at elevations as low as 8,000 feet. In its most benign form, altitude sickness can put a damper on your vacation plans. In more severe manifestations it can be debilitating — and sometimes deadly. If you’re planning to travel to higher elevations, be sure you know how to prevent and treat altitude sickness.
What is altitude sickness?
The phrase “altitude sickness” is an umbrella term for several varieties of illness. The root cause is the same, however: lack of oxygen at high elevations. The symptoms vary, but can include headache, loss of appetite, vomiting, diarrhea, and abdominal pain, all of which can last anywhere from 12 hours to four days.
What are the different types?
Altitude sickness is typically divided into three distinct syndromes:
- Acute Mountain Sickness (AMS): Considered the most common form, AMS involves the symptoms people typically associate with altitude sickness and hangovers: headache, fatigue, loss of appetite, nausea, and occasional vomiting. Symptoms usually resolve within 24 to 72 hours of acclimatization.
- High Altitude Cerebral Edema (HACE): If AMS progresses, it can turn into HACE, which involves the build-up of fluid in the brain. Symptoms include headache, dizziness, blurry vision, and disorientation. Although an important prevention and treatment strategy is hydration, people with more severe forms of altitude sickness often can’t keep water down. HACE is rare but potentially fatal, and can become life-threatening in just a few hours. Descent is the only real treatment.
- High Altitude Pulmonary Edema (HAPE): HAPE typically occurs at higher elevations and involves a build-up of fluid in the lungs. HAPE can happen to anyone at any altitude above 8,000 feet. Even experienced athletes can experience it, so while preparation and training are important, they aren’t guaranteed safeguards. Mild symptoms can include a dry cough and shortness of breath after mild exertion, but more severe types of HAPE involve shortness of breath at rest, confusion, and fever. The only way to alleviate HAPE is to descend — oxygen and descent are life-saving and essential.
How can I prevent altitude sickness?
Luckily, there are ways to sidestep the symptoms of altitude sickness and avoid the more serious complications before and during your trip.
Before You Go:
Ibuprofen was found to significantly reduce the incidence of altitude sickness in a double-blind, placebo-controlled trial of 86 men and women. Take 400 mg of Motrin or Advil in the morning, and then every six hours while at elevation.
Drink two to three liters of water a day to prepare for your trip. Dehydration decreases the body’s ability to acclimatize to higher altitudes.
If you are a regular coffee drinker, make sure that you have caffeine prior to climbing. The effects of caffeine withdrawal mimic the effects of altitude sickness, and are alleviated by caffeine. It’s also a good idea to bring caffeine-containing Excedrin along on the trip for a quick pick-me-up.
Stay Home if You’re Sick
What seems to be a small cold at lower elevations can be serious at higher elevations. It’s imperative to be completely healthy when you begin your journey. Your lungs are already working their hardest to adapt to the thinner air at altitude; any cough or wheeze can compromise that. Use your best judgment and if you’re unsure about whether it’s safe to go, contact your health care provider for advice.
Take the Right Medication
Acetazolamide is a medication often used to prevent and reduce the symptoms of altitude sickness by increasing respiration. The side effects, however, such as increased urination and tingling in the hands and feet, can be similar to the illness itself, so it may not be helpful for everyone. If for some reason you can’t take acetazolamide, speak to your health care provider about other options.
Because it’s important that you continue to eat while at altitude, make sure you are bringing food that is easily tolerated. Treats like chocolate or snacks such as pretzels can be great portable options. Stick with simple flavors; sometimes spicy food can be very nauseating at high altitudes.
During the Trip:
Don’t go too high too fast. Acclimatization is the most important way to avoid symptoms of altitude sickness, so plan for a night or two at 8,000 feet, then ascend no more than 1,600 feet per day.
Climb High, Sleep Low
The old climber’s adage holds true: climb high, sleep low. It’s important to head to higher altitudes during the day as you are trying to acclimatize, but to sleep lower in order to get oxygen. Never sleep at an altitude if you are feeling symptoms of altitude sickness; head down the mountain to sleep in thicker air.
You’ll know if you’re drinking enough water if you’re urinating regularly. If you haven’t urinated in three to four hours, drink more. Higher altitudes require extra fluid consumption.
Protect yourself from the sun by wearing a hat, lip protection, and sunblock. Be sure to wear sunglasses as well to avoid snow blindness, a condition that can occur at higher elevations.
If You Get Sick
If, despite your best efforts, you do begin to feel some of the mild signs of altitude sickness like headache and difficulty breathing, there are a few strategies you can try. Often you can alleviate the symptoms with a few simple tricks:
- Hydrate as much as possible with water and Gatorade
- Take a dose of ibuprofen or Excedrin
- Walk slower, especially while climbing. Try this pattern: Step, step…breathe….step, step…breathe. Sometimes all you need to do is slow down.
If the headache and difficulty breathing continue despite all of the above, the most important thing you can do is descend. Never ever try to “sleep it off” — that could be a deadly decision. Remember, the mountain will always be there.
The One Medical blog is published by One Medical, an innovative primary care practice with offices in Boston, Chicago, Los Angeles, New York, Phoenix, the San Francisco Bay Area, Seattle, and Washington, DC.
Any general advice posted on our blog, website, or app is for informational purposes only and is not intended to replace or substitute for any medical or other advice. The One Medical Group entities and 1Life Healthcare, Inc. make no representations or warranties and expressly disclaim any and all liability concerning any treatment, action by, or effect on any person following the general information offered or provided within or through the blog, website, or app. If you have specific concerns or a situation arises in which you require medical advice, you should consult with an appropriately trained and qualified medical services provider.
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