When we visited Uganda and Rwanda, I was a bit concerned about altitude sickness.
During gorilla treks, it is not unusual to start at around 6,000-7,000 feet and ascend to 9,000-10,000 feet (about 3,000 meters) before ascending back down. And it definitely had been a while since I had done anything strenuous at altitude. I grew up at about 6500 feet, but have been living at sea level or just above for nearly 15 years and can definitely tell the difference now. Fortunately all went fine, and my lack of problems in Uganda and Rwanda meant I was far less concerned when we headed to Bhutan, where passes can be that high or higher, and the Tiger’s Nest is at about 10,240 feet.
Sure, altitude sickness is a well known problem on high-altitude treks, like those in Nepal. But is it really that common in travelers visiting other higher altitude sights? While my doctor and I decided that preventative medication was not something I needed, how many people do take a prescription medication? [Disclaimer, as always, I am not a medical professional. Google is also not a licensed medical professional, much to all of our chagrin. Talk to your doctor for advice.]
So when I ran across this interesting article about acute mountain sickness (AMS) in Cusco, I was definitely interested and a bit surprised by what the authors found.
Is AMS really that common? The authors interviewed 991 travelers, of which nearly half (48.5%) reported AMS. That said, while they did use the common measure typically used to evaluate AMS, a lot of AMS symptoms are non-specific to AMS (i.e. headache, nausea, sleeping disturbances). I think all of us have experienced some of these symptoms while traveling! However, 17.1% of these travelers had severe AMS. This is a bit higher than I was expecting. About 20% of travelers with AMS did alter their travel plans.
So who was less at risk for AMS? Interestingly, people over 60 years old (I guess that’s one perk of aging!), and also those who came from other cities not at sea-level before going to Cusco. Unsurprisingly, those who had recent high altitude exposure also had fewer problems. So get older, spend more time at lower altitude cities, or at higher altitudes.
What about drugs? Only about a third of travelers talked to their physician about AMS, which seems about right considering how many travelers probably don’t see a physician who specializes in travel medicine these days. The authors report 16.6% used acetazolamide to prevent AMS (and travelers reported the acetazolamide did work). I’d be curious to know if those using the drug had previous problems and specifically requested a prescription…
And the myth of the coca leaf? Who hasn’t heard the tale that chewing on a coca leaf will make you feel better at altitude? I don’t know where this story came from, but I think it originally was something passed down from indigenous cultures…needless to say, the authors report that while nearly 63% of the travelers used coca leaf products, the use of coca leaf products was associated with increased AMS frequency.
Yes, you read that right, people that used coca leaf products had more AMS than those that didn’t. Now…let’s remember correlation does not equal causation. So coca leaf may or may not have caused those people to get AMS. It’s just a correlation. And in some ways, it makes a great deal of sense: those who feared getting AMS or had previously experienced AMS, tried coca leaf to alleviate their symptoms.
This article reminds us all to: talk to your doctor before heading to high elevations, especially if you have pre-existing conditions. If you don’t know how you will react to high altitude, give yourself some extra time at your location to find out and acclimate before climbing/hiking. AMS is extremely serious (and high altitude pulmonary edema is deadly), but there are mitigations and early treatment can help you get on your way and back to enjoying your travels.
Citation: Salazar, H., Swanson, J., Mozo, K., White, A.C., Cabada, M.M. 2012. “Acute Mountain Sickness Impact Among Travelers to Cusco, Peru.” Journal of Travel Medicine. 19(4): 220-225.