Stay healthy & happy while high: Tips on how to prevent and treat Altitude Sickness, or Acute Mountain Sickness (AMS)
The idea of altitude sickness can be intimidating, but it doesn’t have to be! Because Ladakh, one of our tour specialities and home away from home, is a high-altitude destination, we understand the importance of keeping our guests (and ourselves) as safe as possible. Below you’ll find our tips for staying healthy at high altitudes and the best current medical advice out there.

During our 2019 Tibet exploration we spent the night at the base of Everest at 16,500 feet. However, our travels in the Himalayas of Ladakh regularly take us over mountain passes 17,000 feet and higher.
What is meant by “high altitude”?
These are the commonly accepted heights when talking about altitude:
- High altitude: 8,000 – 12,000 feet (2,438 – 3,658 meters)
- Very high altitude: 12,000 – 18,000 feet (3,658 – 5,487 meters)
- Extremely high altitude: 18,000+ feet (5,500+ meters)
It is uncommon to develop AMS below 8,000 feet (this is the altitude that planes are pressurized to–more on that later). However, if you are particularly sensitive, you could exhibit symptoms lower than that.
Why does altitude have an effect on the body?
At sea level, we are at the bottom of an ocean–an ocean of air! You’ve heard of “air pressure” before? That’s because air has weight and exerts pressure on us at all times. At sea level, the pressure on our bodies is the equivalent weight of thirty feet of water was pressing down on us. It makes sense, then, that when you go higher, there is less atmosphere pressing down on you. It’s like going from the bottom of the deep end of the pool to the bottom of the shallow end. Given this change in pressure, it’s not surprising that the body undergoes changes in order to adapt.
It’s easy to see the effect around you, though. If you go to a shop, you may notice all the bags of chips are bloated with air; if they were packed at a lower altitude and shipped to a high altitude, the air inside will naturally expand without that same external pressure being exerted on it. (A practical note: if you have toiletries like lotion or gels in thin plastic tubes or bottles, be sure to squeeze the air out of them when you pack at a lower altitude. This will prevent them from spewing out of their containers when you open them at a higher altitude!)
You may have heard that there is “less oxygen” at altitude, but the truth is there is just less of everything that makes up our atmosphere. The air at sea level and the air at 15,000 feet both contain 21% oxygen, but because there is less total air, there is less total oxygen. Here’s a neat calculator that allows you to input an altitude and it tells you how much oxygen is present as compared to sea level (don’t forget to toggle between feet and meters, if you need to).
What is a normal response to altitude?
According to BaseCamp.MD:
Certain normal physiologic changes occur in every person who goes to altitude:
- Hyperventilation (breathing faster, deeper, or both)
- Shortness of breath during exertion
- Changed breathing pattern at night
- Awakening frequently at night
- Increased urination
While some changes are normal and to be expected, you need to know the symptoms of Acute Mountain Sickness (AMS) so you can monitor yourself (and your friends) and to be sure that AMS symptoms don’t lead to HAPE (high altitude pulmonary edema) or HACE (high altitude cerebral edema), two very serious disorders that can be life-threatening.
Symptoms of Acute Mountain Sickness (AMS)
Before we go any further, let us say that AMS is not life-threatening and it’s not uncommon; Princeton reports that 75% of people experience mild AMS at an altitude over 10,000 feet.
The symptoms of AMS include the following:
- Headache
- Dizziness
- Loss of appetite
- Nausea/vomiting
- Fatigue/loss of energy
- Insomnia
- Frequent urination
Headaches are the classic symptom but a headache alone does not mean you have AMS.
Another effect of altitude to be aware of is a changed breathing pattern at night called periodic breathing or Cheynes-Stokes breathing. In periodic breathing, the breath alternates between shallow and deep breathing. This is completely a normal response at altitude and is the body’s way of regulating the acidity in your blood.
According to TheTravelDoctor.co.uk, “Mild AMS does not interfere with normal activity and symptoms generally subside within two to four days as the body acclimatises.”
There is a questionnaire designed by experts to help you assess yourself (and your friends) at altitude called the Lake Louise Test. You can click here for the test form which you can save on your phone and keep handy. Check in with travel companions or tour guide, or if you are all alone, text a friend at home every day with how you feel, as a record for yourself to refer to.
Don’t forget to read about HACE (high altitude cerebral edema or fluid on the brain) and HAPE (high altitude pulmonary edema or fluid in the lungs) below. Unchecked AMS symptoms can result in more serious, potentially fatal altitude illnesses.
How to Prevent Altitude Sickness
The best way to approach altitude is slowly. However, you are more than likely going to be flying into high altitude area, be it Cusco, Ladakh, or Lhasa, so there’s no way to gradually ascend as hikers would.
One of the most important things is to take it easy the first 24-36 hours. We mean it! Even if you feel great, it is best to rest and not push yourself physically. You may be anxious to see your new destination, but it is safer and much better in the long run if you start slow. Stick around your hotel and don’t poke around more than a couple of blocks (at most).
In addition to rest, there are some medications or supplements you can take to make your transition to altitude easier.
Diamox (Acetazolamide)
Diamox is used both as a preventative and treatment (in higher doses) for AMS; its generic name is Acetazolamide. If you’re curious about the mechanism in a nutshell, Diamox (indirectly) signals to the body it needs to breathe more. In that way it doesn’t mask symptoms of AMS, it actually helps accelerate your body’s natural acclimatization processes. If you want to know more about the fascinating process, read more over at CIWEC clinic, a favorite clinic of ours in Kathmandu, Nepal.
You can read about the side effects of Diamox here, and please check for any drug interactions with your prescription or OTC drugs here. Ideally, your prescribing physician will help you with this, as well. (Anecdotally: BJ and I both took Diamox to prepare for an overnight at 16,500 feet on the Tibetan side of Mt. Everest and we both noticed tingly extremities. It can also make carbonated drinks taste strange, oddly enough.)
Ibuprofen
Studies have shown that ibuprofen is effective in reducing the incidence of acute mountain sickness (AMS). The dose in the study was 600mg three times a day; it’s worth noting that we (and our guests) have success with 400mg three times a day.
You can read more about ibuprofen’s efficacy in high altitudes from Stanford School of Medicine.
Start taking the ibuprofen 24 hours before the flight to your high-altitude destination. Continue taking it for 24-48 hours after you arrive and then see how you feel. Continue as needed. And all of this, of course, if only if you and your doctor have determined that ibuprofen is safe for you.
Remember: Ibuprofen means ibuprofen. In the U.S., the brand names of ibuprofen are Motrin & Advil; plenty of companies also sell generic ibuprofen (Target, Walgreens, Walmart, etc). This does not mean Tylenol or any other form of acetaminophen.
Ginkgo Biloba
You might have heard of this herb before, used widely in brain health and memory supplements. However, it’s also been studied (here and here) for its effect of preventing altitude sickness. Animal studies show it effective in preventing HAPE (high altitude pulmonary edema). While there are some inconsistencies in the studies, much of that is attributed to differing qualities of the ginkgo used. I’m a fan of the brands Doctor’s Best and Gaia Herbs.
Water!
Make sure you’re drinking enough water, as some of the symptoms of AMS are the same as dehydration. Higher altitudes are often associated with dehydration because of increased urine output. Also, the air is typically dryer and your breath more rapid, leading to a greater loss of bodily fluids through the breath. It’s also best to avoid alcohol (or any central nervous system depressant) because of its effect of depressing the breath.
Chlorophyll
The use of chlorophyll is purely anecdotal but worth mentioning. Yes, this is the same chlorophyll that makes plants green! The theory here is that chlorophyll supplements fortify your blood cells, enhancing their oxygen-carrying capabilities (This short video is how the company Herbs, Etc explains the mechanism.) Only one study I can find remotely suggests chlorophyll’s blood-boosting ability, but it’s indirect at best. However, many people swear by it and for most people it’s a harmless natural product. Perhaps you can use this as an excuse to up your intake of green leafy vegetables with their abundance of nutrients and fiber, as well as chlorophyll!
If you decide to take chlorophyll, I would highly suggest getting the pills instead of the liquid if you are traveling, as the liquid stains if spilled. Remember that your stools may be tinted a dark green when taking this product—don’t be startled!
Coca Leaves
If you travel to the Andes Mountains in South America, chances are you will encounter coca tea, in a teabag or loose-leaf form. There’s evidence that humans have been using coca leaves medicinally for at least 3,000 years, although there isn’t a big body of modern research on the effects of coca on the body at altitude.
To answer your question, yes, this is the same coca that cocaine is made from (although cocaine is a highly concentrated and adulterated version of just one of coca’s numerous alkaloids. In our experience, coca tea gives you the same buzz as a cup of black tea. And to answer your next question…
Will Coca Tea make me test positive for cocaine on a drug test?
Yes, coca leaves and tea bags can create a positive for a cocaine drug test. You’ll often find “decocainized” tea bags; similar to decaffeination in coffee, coca tea can be decocainized. However, just as decaffeinated coffee retains a small quantity of caffeine, decocainized coca tea will still contain a small quantity of organic coca alkaloids.
A quick yak break
The monks at Rongbuk Monastery at the base of Everest in Tibet threw out some old bread for the local yaks. BJ decided to help one out with a handfeeding!
How to Best Plan an Itinerary to Avoid Altitude Sickness
We plan all of our high altitude itineraries very carefully and intentionally, and we’re happy to share some of those tips with you.
Plan a day of rest upon arrival
We’re serious–and I mean at least 24 hours, not just the rest of the daylight hours upon arrival. Extend your stay by a day if you must in order to honor this recommendation, but please do it. Better to start slow and acclimate more efficiently than hit the ground running and feel like garbage on your whole vacation (or worse, get seriously ill).
Start as low as you can
When you are able to, go to the lowest part of your journey upon arrival in a high-altitude region. For example: When visiting Machu Picchu in Peru, many people will fly into Cusco (11,152 ft/3399m) and really struggle before heading down to Machu Picchu. Instead, upon arrival in Cusco, immediately make your way to Aguas Calientes, the town at the base of Machu Picchu. Aguas Calientes rests at 6,693 ft/2040m altitude and is a great home base from which to visit the ruins Machu Picchu (7,972 ft/2430m). Then, you can make your way back up to Cusco in one shot, or spread it out and spend a night or two in Ollantaytambo (9,160 ft/2791m) or Urubamba (9,420 ft/2871m). That way your ascent to Cusco is a bit more gradual.
Get creative with your itinerary and always try to start as low as you can, even if it’s only by 500 to 1000 feet!
Choose a Dreamliner or Airbus A350 XWB
You may think you’ve never been to 8,000 feet, but if you’ve ever been on an airplane, you have. We don’t mean literally–airplanes fly much higher, at around 38,000 feet—but the inside of the cabin is pressurized to the equivalent of 8,000 feet. However, the Boeing 787 Dreamliner is pressurized to 6,000 feet, and it also boasts a higher humidity. It is thought that this lower “altitude” makes for a more pleasant journey and fewer jet lag symptoms upon arrival. Now, if you’re flying to a high altitude, getting there on a Dreamliner isn’t going to make much of a difference, but it’s a good tip to know for future long-haul flights.
How to Treat Altitude Sickness
With mild AMS symptoms, you can stay at the same altitude to see if your symptoms resolve. If you have not yet taken Diamox or ibuprofen, you can try that. CIWEC Clinic advises that “Diamox 250mg two or three times a day can be used to treat mild-moderate symptoms.” However, please follow the plan that you and your prescribing doctor have created.
However, if your symptoms worsen, medical attention (and, ultimately, descent) is required. If you are in a high-altitude city that sees lots of tourists, the hospitals will be well-prepared to handle altitude-related emergencies. There are drugs that can be used to address the swelling and devices such as the Gamow Bag, a portable hyperbaric bag, to mimic a higher air pressure until you can be flown to a truly lower altitude.
HACE and HAPE
Mild symptoms of AMS are not inherently dangerous and they are very common. However, they can be a warning sign that you are not adjusting to the altitude well.
It’s crucial to keep tabs on your symptoms because two other conditions can develop as a result of altitude: HACE (high altitude cerebral edema, or fluid on the brain) and HAPE (high altitude pulmonary edema, or fluid in the lungs). Both HACE and HAPE can be fatal and require immediate medical attention and a descent in altitude.
HACE
The key to diagnosing HACE is a change in coordination and/or the ability to think. There may be confusion, disorientation, or lethargy. A person with HACE may have trouble with coordination, similar to a drunk person; one test for this is having them walk a straight line heel-to-toe.
Please see the following resources to learn more about HACE:
HAPE
Symptoms of HAPE include
- Extreme fatigue
- Breathlessness at rest
- Fast, shallow breathing
- Cough, possibly productive of frothy or pink sputum
- Gurgling or rattling breaths
- Chest tightness, fullness, or congestion
- Blue or gray lips or fingernails
- Drowsiness
Note: HAPE usually occurs on the second night after ascent to altitude
Please see the following resources to learn more about HAPE:
Closing thoughts
Please remember to be honest with yourself (and your tour guide) about any symptoms you might be experiencing. You might be the only one in your group experiencing them; this might be your 20th time at altitude but your first time with symptoms; you may be worried about slowing down the trip or being a bother. Please put all those concerns or doubts aside and put your health first; it’s crucial to share your symptoms with a group leader or a friend. AMS is not something to “tough out,” it’s something to carefully monitor.
Do I need Travel Insurance?
We believe the answer is Yes! We require our guests to carry travel insurance, and we think it’s an important safety net for all travelers. It’s a small price to pay for peace of mind should something unexpected happen during your journey. Click here to find out more about where to start your search for travel insurance.
*All of the information here is for reference purposes only and is not intended to substitute for advice from a licensed healthcare professional. These statements have not been evaluated by the FDA and are not intended to diagnose, treat, cure or prevent any health condition or disease. If you are experiencing medical issues, you should contact your medical health care provider.
Other resources on this topic you might find interesting:
- https://www.altitude.org/altitude-sickness
- https://www.wemjournal.org/article/S1080-6032(19)30090-0/fulltext
- https://wwwnc.cdc.gov/travel/yellowbook/2020/noninfectious-health-risks/high-altitude-travel-and-altitude-illness
- https://wwwnc.cdc.gov/travel/page/travel-to-high-altitudes
- https://ciwec-clinic.com/health-articles/altitude-illness-advice-for-trekkers/
- https://unofficialacclimatizationguideline.blogspot.com/p/normal-acclimatization.html
- https://www.nhs.uk/conditions/altitude-sickness/
- https://www.fitfortravel.nhs.uk/advice/general-travel-health-advice/altitude-and-travel
- https://www.wikihow.com/Prevent-Altitude-Sickness
- http://www.basecampmd.com/https://www.yowangdu.com/tibet-travel/avoiding-altitude-sickness.html
- http://www.traveldoctor.co.uk/altitude.htmhttps://my.clevelandclinic.org/health/diseases/15111-altitude-sickness
Popular high-altitude destinations worldwide:
- Mt. Kilimanjaro, Tanzania = 19,341 feet (5,895m)
- Everest Base Camp = 17,598 feet (5364m)
- Annapurna Sanctuary & Base Camp, Nepal = 13,550 feet (4130m)
- Puno [Lake Titicaca], Peru = 12,556 feet (3,830m)
- Lhasa, Tibet = 12,002 feet (3,658m)
- La Paz, Bolivia = 11,942 feet (3640m)
- Leh, Ladakh, India = 11,000 feet (3,500m)
- Cusco, Peru (aka Cuzco) = 11,152 feet (3399m)
- Tiger’s Nest (Paro Taktsang), Bhutan = 10,232 feet (3118m)
- Breckenridge, CO, USA = 9,600 ft (2,926m)
- Quito, Ecuador = 9,350 feet (2,850m)
- Telluride, Col, USA = 8,750 ft (2,667m)
- Cuenca, Ecuador = 8,366 feet (2,550m)
- Machu Picchu, Peru = 7,970 feet (2430m)
- Sugarloaf, CO, USA = 7,842 ft (2,390m)
- Thimphu, Bhutan = 7,656 feet (2320m)
- Mexico City, Mexico = 7,380 feet (2250m)
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