You might have heard of it, or even seen a video or two about it featuring climbers in the Alps or the Himalayas, and yet, not really know what altitude sickness is.
But what every responsible mountaineer needs to know is that the more serious types of altitude sickness are life-threatening and need emergency care. And because emergency rooms are usually out of the question while you’re up there, you need to be aware of what to look out for and what to do on the spot.
Read on to learn more (or refresh what you already know) about staying healthy and safe on your ascent, so you can keep on adventuring among the heights for years to come.
What Exactly Is Altitude Sickness?
The air gets thinner the higher you climb, and when your body isn’t able or hasn’t had time to adapt to breathing in less oxygen, you can develop altitude sickness. You can start developing symptoms once you climb past 8,000 feet2,400 meters above sea level; to give you an idea, Mount Whitney (at the end of the John Muir Trail) is 14,505 feet,4,421 meters, and Mount Everest is over 29,000 feet.8,800 meters.
Who Gets Altitude Sickness?
Anyone who isn’t used to high altitudes usually has altitude sickness, but people hardly get it below 8,000 feet.2,400 meters. (Although symptoms can start to show at around 6,000 feet1,800 meters or even lower for some people.) Anyone who rushes to climb to 11,000 feet3,350 meters is almost certainly going to develop it, which is why a controlled ascent, or going up at the right pace, is absolutely essential.
People With Higher Risk
Some people, however, are more likely to develop altitude sickness than others, and contrary to what you might have heard, it has nothing at all to do with being younger or more fit.
Very simply, your risk for altitude sickness increases the higher you climb, or if you usually live in a low-altitude area. You’re also more at risk if you’ve had altitude sickness before. Mountaineers using drugs and alcohol (for medical purposes or otherwise) are also at a higher risk.
What Are The Different Types Of Altitude Sickness?
The three types of altitude sickness differ according to the symptoms you have, how severe they are, and the organs that are affected. Here’s a quick overview to help you differentiate:
| Altitude Sickness | AMS | HACE | HAPE |
|---|---|---|---|
| Definition | Difficulty acclimatizing | Swelling of the brain | Lungs filling with fluid |
| Symptoms | Headache Lethargy Nausea Nosebleed Swollen hands and feet | Headache Lethargy Confusion Loss of muscle coordination Fainting | Difficulty breathing Coughing up blood Rapid heart rate Loss of muscle coordination Purple lips |
| Treatment | Ibuprofen Acetaminophen Acetazolamide Dexamethasone Oxygen | Dexamethasone Ibuprofen Hyperbaric Therapy Oxygen | Nifedipine Hyperbaric Therapy |
Regardless of type, you should stop going any higher as soon as altitude sickness symptoms start to show. You should also consult a doctor before taking any of the medications mentioned here (in any case, you’re likely to need a prescription to purchase them). Read on to learn more about each type and what you can do to help yourself and fellow mountaineers.
Acute Mountain Sickness (AMS)
AMS is probably what most of us have in mind when we hear “altitude sickness” and what many new mountaineers experience if they go up too fast. The symptoms can be bad enough to ruin your climb, and if not addressed promptly, could develop into the other types of altitude sickness which are far more serious.
AMS Symptoms
AMS starts to show as early as 6,000 feet1,800 meters up for some people after six to 10 hours, up to 24 to 36 hours. They get headaches that don’t go away, feel dizzy or lightheaded, or have a hard time falling asleep. They also feel nauseous (and sometimes vomit). A general feeling of weakness and loss of appetite are also common symptoms accompanied by swollen hands and feet.
At 9,000 feet,2,750 meters, mountaineers might also develop a retinal hemorrhage or a small spot of bleeding behind the eye, causing blurred vision.
First Aid And Treatment
Stop climbing and rest as soon as you notice these symptoms. Have something to eat (more often, if you can manage it) and drink water.
Altitude sickness medicine you can take for AMS includes Ibuprofen, Dexamethasone, and Acetaminophen or Tylenol, but do not take Tylenol PM or any medication that contains sleep aids (as these contain respiratory suppressants). Acetazolamide or Diamox can also help with swelling when taken in the prescribed dosage.
Should symptoms persist or worsen, head back down to a lower altitude for one to two days for rest to allow the symptoms to clear up.
High Altitude Cerebral Edema (HACE)
Symptoms of HACE overlap with those of AMS as doctors usually classify both types of altitude sickness together. With AMS, there is a slight swelling of the brain but not enough for it to be considered HACE, which typically develops once you pass 9,000 feet2,750 meters up. Do note that it can only take a few hours for HACE to be fatal, which is why prompt treatment is so crucial.
HACE Symptoms
On top of the persistent headaches, dizziness, and lethargy that comes with AMS, HACE symptoms include drowsiness, confusion, an altered level of responsiveness (ALOR), and even hallucinations. A mountaineer might even also begin to stagger or lose muscle coordination, or lose consciousness.
Symptoms start to show in 12 to 24 hours, and if you notice any weird or unusual behavior in your fellow mountaineer, that person could have HACE. One way to test for it on the slopes is to ask the person to walk in a straight line, heel to toe, as a person with HACE will have a hard time doing this.
First Aid And Treatment
Stop climbing and head back down immediately as soon as these symptoms are observed. Then start taking oxygen and Dexamethasone.
Dexamethasone is a steroid medication you can get with a prescription, and it helps reduce the swelling on the brain. If you’ve been taking this medication for more than 10 days, you’ll have to taper it off rather than just stop taking it to avoid complications. If the headaches are really bad, you can take Ibuprofen in doctor-prescribed dosages.
If the weather or other conditions make it impossible to descend right away, start hyperbaric therapy using a Gamow bag. Take note that some Gamow bags deliver oxygen as well as adjust pressure to mimic lower altitudes, and that using oxygen inside a Gamow bag may be a fire hazard.
High Altitude Pulmonary Edema (HAPE)
Not only is HAPE the most serious type of high altitude sickness, but it may even be accompanied by HACE. HAPE is when fluid accumulates in the lungs due to less oxygen intake causing blood vessels in the lungs to tighten up. This type of high altitude sickness can be fatal in about 12 to 40 hours if a person were to rush up the slopes to 8,000 feet.2,400 meters.
HAPE Symptoms
In 24 to 96 hours at the critical altitude, a mountaineer with HAPE will have a hard time breathing or have shortness of breath, and then start to have a dry, then a wet cough. The person could also start to cough up blood or have bloody or pink spit, and the lips and nails may also start to turn purple, blue, or gray.
On top of an overall feeling of weakness and ALOR, the mountaineer may also not be able to move around very much and lose muscle coordination. The person may also have a fever and rapid heart rate and breathing accompanied by gurgling noises. These symptoms usually come on at night and get worse during strenuous activity.
First Aid And Treatment
Stop climbing and head back down immediately as soon as these symptoms are observed. You will need to help a mountaineer with HAPE down to avoid making the symptoms worse with added exertion. Start taking oxygen at high flow (2 to 4 liters per minute) if possible.
A Gamow bag will be needed if you can’t go back down right away, and the person with HAPE can take Nifedipine according to the prescribed dosage. Do take note, however, that Nifedipine becomes unnecessary if you can descend immediately. Descent must not be delayed as much as possible.
How Long Does It Take To Recover From Altitude Sickness?
Most mountaineers start to feel better as soon as they start heading down, and how soon you recover depends on how severe your altitude sickness was and what was done to address the symptoms. It can take several hours or one to two days for symptoms to go away.
Can You Prevent Altitude Sickness?
Absolutely. The main way to prevent altitude sickness is to climb gradually or at the right pace. The US Centers for Disease Control and Prevention say you should avoid rushing to climb more than 9,000 feet2,750 meters in one day, and that after that point, you should climb no more than 1,600 feet500 meters per day.
Acclimatization
Once you hit about 8,200 feet,2,500 meters, give your body time to get used to the high altitude by resting for one day. That means avoiding strenuous activity (and skipping alcohol). If you climb any higher, every third day should be spent resting, as well. If you plan on going higher than 14,000 feet,4,250 meters, rest for two days for every 3,300 feet1,000 meters after that. Also, be sure to stay hydrated as you ascend.
If you can manage it, head back down to sleep at a lower altitude, which can help ease altitude sickness symptoms. Also, much of the altitude sickness medicine mentioned above can be used to prevent as well as treat each type. You can likewise take prescribed dosages of Sildenafil and Tadalafil to help prevent HAPE. Again, consult a doctor before taking any of these medications.
Training
It is also possible to train for high altitudes to prevent altitude sickness. This training can include regular weekend hiking that gradually takes you to higher altitudes with each hike. If you’re planning to climb really high, try to have at least one of these training sessions take you up 9,000 feet2,750 meters before your actual climb.
Spending five or more days at a time at higher altitudes can also help you acclimatize. You can even get started before leaving home by wearing an altitude mask or sleeping in an altitude tent.
What You Really Need To Know About Altitude Sickness
To wrap up this handy mountaineer’s guide, here are arguably the two most important things you need to bear in mind in treating and preventing altitude sickness.
Summit Fever
It may happen that altitude sickness symptoms set in right when you can practically touch the summit (at least with your eyes). As sorely tempting as it is to ignore the symptoms and to just tough it out, stop climbing and head back down immediately. Don’t let summit fever place your health, or even your life (or the life of your fellow mountaineer) in jeopardy.
Groupthink
Peer pressure can force you (or the mountaineering buddy with you) to keep pushing on for the top, even if you feel, or recognize the altitude sickness symptoms. It can be downright mortifying to ask others to stop and turn right around just for you, especially if no one else seems to be affected by the altitude. But trust us when we say speaking up is the right thing to do.
As any mountaineer will tell you, getting up there and getting to the top isn’t just about physical training but mental conditioning, too. And a huge part of that conditioning is understanding your limits, and knowing when to take risks, for others, as well as yourself. When it comes to altitude sickness, it’s safe to say the risk is never worth it.
As soon as you are able, see a doctor or go to the hospital for professional altitude sickness treatment.
References:
- https://my.clevelandclinic.org/health/diseases/15111-altitude-sickness
- https://wwwnc.cdc.gov/travel/page/travel-to-high-altitudes
- https://www.merckmanuals.com/home/quick-facts-injuries-and-poisoning/altitude-sickness/altitude-sickness
- https://wildsafe.org/resources/ask-the-experts/altitude-safety-101/altitude-illnesses/
- https://www.health.harvard.edu/a_to_z/altitude-sickness-a-to-z
- https://iantaylortrekking.com/blog/how-do-you-train-for-high-altitude-and-low-oxygen-environments/
- https://www.yowangdu.com/tibet-travel/avoiding-altitude-sickness.html
- https://www.espritmontagne.com/en/b_370_avoid-acute-mountain-sickness.php
- https://www.kilimanjarobrothers.com/gamow-bag-kilimanjaro-safety-equipment/#:~:text=The%20Gamow%20Bag%20is%20portable,and%202%20feet%20in%20diameter.
- https://my.clevelandclinic.org/health/drugs/18976-acetazolamide-oral-tablets
- https://www.cdc.gov/yellow-book/hcp/environmental-hazards-risks/high-altitude-travel-and-altitude-illness.html
- https://www.backpacker.com/survival/summit-fever-has-a-body-count-dont-become-a-statistic/
The information in this article, including but not limited to text, graphics, and images are for informational purposes only. This information is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your doctor or a qualified healthcare provider before taking any medication or undergoing training, and never disregard nor delay professional medical advice because of this article.
