How to Acclimate to High Altitude and Avoid Altitude Sickness

If you are new to high altitudes or are unacclimated there is a high chance you will feel some of the symptoms of altitude sickness. Do not worry though! There are ways to mitigate the affects of altitude sickness and get you hiking 14ers.

I live at over 6,000ft and make weekly trips to 10,000ft. Occasionally, I will make trips to 12,000ft to 14,000ft. I have also done my fair share of moving out of Colorado and back to the state, so I understand everyone’s struggle with trying to get acclimated. I have seen it plenty of times firsthand too with my friends that make weekend trips out to the Rockies.

Understanding your limits and how to get acclimated is important to remain safe and make the most of your trip to higher elevations. A beautiful hike can turn into a painful treck if you are not careful. I have even found myself in one of those nightmare situations, which is part of the inspiration to writing this guide. I had moved out of Colorado for 9 months and returned in late May. I gave my self about two weeks to acclimate but did not take any of the proactive steps to mitigate altitude sickness. I had been feeling fine and decided to do a hike up a 14er with a friend. It was a very eventful hike, but long story short we made it to tree line (about 11,500ft). Once at tree line we both started to feel the affects of altitude sickness. Being around 10 miles into the hike we fell to the sunk cost fallacy and decided to try keep pushing. With every switchback we got more and more lightheaded, out of breath, and dizzy. At some points nausea started to kick in. We got to a point where we could only hike 100ft at a time and decided to turn around. A combination of a storm and altitude sickness caused us to spend the night on the side of the mountain. I want others to know how to acclimate to high altitudes to hopefully save you from an experience like mine.

Altitude sickness is a physical distress from difficulty adjusting to lower oxygen levels that are a result of higher altitudes.

As you go up in altitude the atmospheric pressure decreases exponentially. This is the same reason why water bottles tend to expand on airplanes after taking off and the cabin pressure is decreased. Since atmospheric pressure decreases so does the amount of oxygen your body can take in. This is the root cause of altitude sickness (the lack of oxygen). And remember, as you go up in elevation the amount of oxygen available decreases exponentially not linearly.

Types of altitude sickness

AMS – Acute Mountain Sickness

The most common type of a altitude sickness is acute mountain sickness. This is the type that about 75% of people experience symptoms of. These symptoms are comparable to a hangover: dizziness, headache, fatigue, and nausea. This is the most benign type of altitude sickness. Other more severe forms require medical attention while this form can be self-treated.

HAPE – High Altitude Pulmonary Edema

A high altitude pulmonary edema is a build up of fluid in the longs triggered by high altitudes. It is theorized that high altitude pulmonary edema is caused by the blood vessels in the lungs constricting and leaking fluid which causes difficulty in breathing. The sacs in the lungs that typically exchange oxygen for carbon dioxide then fill with liquid and are unable to do their job.

This is a severe form of altitude sickness and can be dangerous or life threatening. If you feel you have HAPE you should seek medical attention.

HACE – High Altitude Cerebral Edema

High altitude cerebral edema is the most severe form of altitude sickness. It is brough on when there is fluid in the brain. This is not only dangerous but is life threatening. Medical attention should be sought immediately.

Symptoms of altitude sickness

The symptoms of altitude sickness are distinct and noticeable. The symptoms are most comparable to that of a hangover. You will notice symptoms within 12 to 24 hours of arriving at higher altitudes and can be accelerated by activity. Mild cases can be self-treated with over-the-counter medication while moderate cases will get worse over time and medication will not help.

Common symptoms include:

• Headache
• Dizziness
• Nausea
• Vomiting
• Fatigue
• Shortness of breath
• Problems sleeping
• Loss of appetite

Some moderate symptoms include:

• Loss of coordination or disorientation
• Severe headaches
• Tightness of the chest

Severe symptoms such as seen in HAPE and HACE include:

• Confusion
• Shortness of breath after resting
• Inability to walk
• Coughing up white or pink frothy substances
• Coma

It is unlikely to experience a HAPE or HACE, but it is important to monitor symptoms just in case.

It is also very common to come to higher elevations and not experience any symptoms until physical exertion. This is important to keep in mind. I have had friends come and not feel symptoms, then after going for a 3 mile jog they are only able to make it one mile. They never have a problem running at sea level, but after a mile at altitude they experience difficulty breathing and a acute altitude sickness.

Although there are dangers with altitude sickness the vast majority of cases and consequences are minimal and benign. In mild cases, it is an inconvenience to your trip. For sever cases like HAPE and HACE medical attention is required.

Even though the symptoms for mild cases of acute mountain sickness are more of an inconvenience they can pose non-medical risks. For instance, if you are unacclimated and did not take any precautions and you decide to hike a 14er. You could find yourself in a bad situation, much like I did. You could get deep into the mountains and start to get dizzy, nauseous, and have exaggerated fatigue. The symptoms alone are not dangerous, but the situation you are in make it a potentially dangerous situation. Even more so if you are not able to find your way back and get off the mountain. Another potential danger is driving and rapidly gaining elevation. I have only witnessed this being an issue in extreme circumstances, but it should still be a consideration. For example, driving Pikes Peak brings you from 6,000ft to over 14,000ft in under an hour and a half. It has been reported that drivers of the Pikes Peak Hill Climb, a race up the mountain with the record being under 8 min, have had to stop racing because the rapid elevation gain gave them altitude sickness. Also remember the risk is minimal for sight seers because these racers do it sub 8 min and can hit heart rates of 200 beats per minute.

It is very important that if you feel any symptoms to closely monitor them. Mild symptoms may be an inconvenience, or they may be a warning sign of something to come. If you are feeling symptoms bellow 8,000ft keep in mind your condition will most likely worsen when gaining altitude. If you feel symptoms do not attempt to overexert yourself or hike up to 14,000ft.

• Training hikes: Do not plan on a high-altitude hike if you struggle doing a hike on flat ground at low elevation. These hikes are significantly more strenuous. Make sure to go out and get plenty of hiking in and running is even better. If you can, hike with a weighted vest. The weight will make you a stronger hiker and prepare you for altitude. At altitude, you get fatigued a lot easier and a normal backpack becomes a lot heavier. Training with weights will help prepare for the added fatigue. If you do not have a weighted vest, then use a backpack with water or weights in it. Weights are ideal as you know how much extra you are carrying, but water is just as good. Water weight can definitely add up and you should practice hiking with extra water anyways. When you are hiking at altitude you should be drinking lots of water, which makes practicing with extra water a good option.
• Incline training: Hiking at altitude is all about elevation change. You are just about guaranteed to be hiking up an incline. The best way to practice for uphill hiking is by going out and doing some. If you are from a super flat area get on the stair stepper or find a hill to run some hills on. Do as many sets as you can running up the hill and walking back down. Walking down will also get you prepared for coming back from a summit in a controlled way. Try not to stomp and give yourself shin splits or hurt your knees. Each time you go to the hill try to do one or two more sets than you did last time.
• Practice in higher altitudes: This may not be applicable for everyone, but if you have a place where you can go up 1,000 feet in altitude hike to the top as much as possible. Also try to spend time up there to get at least a little feel of elevation change. It may not compare to the 14,000 feet you will be summitting, but every little bit helps.

Get used to drinking a lot of water

Water is incredibly important at higher altitudes. If you drink the same amount as you usually do you will most likely experience dehydration and cotton mouth at higher altitudes. This can get dangerous when out in the back country. At altitude you will need an extra liter to a liter and a half of water. This is because your body is working in overdrive when not acclimated. Not drinking the proper amount of water can lead to dehydration which has similar symptoms as altitude sickness. Therefore, if you feel altitude sick, drink extra water and monitor symptoms. Who knows, you may have just been dehydrated. The best way to check your hydration levels is by your urine. If it is clear you are also in the clear. The darker it is the more you need to drink.

Learn breathing techniques

Hiking at altitude is not a race. Instead, it is a rhythm. You need to find your pace while hiking, but more importantly you need to find a good breathing pace and rhythm. Doing yoga at lower altitudes will help practice breathing rhythms that can be used to keep pace at higher altitudes.

Eat more

For the same reason you need to drink more water you also need to eat more. Your body is working extra hard at higher altitudes hence needs more fuel. Also, if you are doing a lot of outdoor activities you are probably using more energy than you normally do. All the more reason you need to eat more and compensate for the loss.

Drink lots of water

Drinking more water is one of the most important things. At altitude, your body gets dehydrated a lot faster. You should be drinking between a liter and a liter and a half more than what you normally drink. Likes mentioned earlier, the symptoms of dehydration are like those of altitude sickness. There are times where people are just dehydrated and think they have altitude sickness. So, make sure you drink plenty of water.

Allow yourself the most time you can to acclimate

Regardless of how you have prepared for the altitude, give yourself the most time to acclimate. To get fully acclimated will take months, but to get as acclimated as you can make sure you save the most strenuous adventures for last. If you plan on summitting a 14er, try to make that the last stop of the trip. This gives you the most time to acclimate to the altitude.

Take over the counter medication

If you experience symptoms, make sure to give your self-time before going higher in elevation. Symptoms can stay anywhere from 12 hours to 4 days. Do not worry though, there is over the counter medication that can help. Ibuprofen, Advil, Motrin, or Aleve can all help with altitude sickness symptoms.

Eat potassium

Increased altitude leads to dehydration and dehydration leads to lower potassium. Muscle cramping is the most common symptom of low potassium. Make sure to eat foods like bananas, yogurt, and avocados.

Do know your limit

Know your physical limits. At altitude everything becomes more difficult, even going for a walk. If you can hike 10 miles at sea level do not assume you can do it on inclines at elevation. When hiking, by the time you feel altitude sickness it is usually too late to salvage the hike. Do not fall to sunk cost fallacy like I have. That is a mistake you will only make once. Just about every trail in Colorado is an out and back trail. This means you hike to a summit then descend back down. If you get altitude sickness on the way to the summit, you must hike all the way back down which is not very fun while feeling the effects.

Do not overexert yourself

You should know your limits and more importantly you should not exceed these limits. Typically, while hiking if you feel fatigue or exhaustion you pull over to the side and rest. Once rested, you carry on. This is not as simple when unacclimated at altitude. When you feel exhausted and fatigued it takes substantially longer to recover. It is not as easy as sitting and taking a couple minute break. When you sit for substantially longer than usual and realize your symptoms are not going away remember that the higher you go your symptoms will only get worse.

Do not drink alcohol

Not drinking alcohol is something you will hear a lot when asking what not to do at altitude. Altitude sickness can feel just like a hangover so combining the two is not a very good combination. Your body also requires more water and alcohol dehydrates you which can lead to heavier alcohol consumption consequences. On top of all that, because of the thinner air you feel the effects of alcohol faster. When out drinking don’t assume you can have the same number of drinks as sea level and still be ok to drive.

With all of that said, drinking alcohol while unacclimated at altitude is not the end of the world. With all the breweries in Colorado it is hard to stay away from all the beer. So, when you drink just drink responsibly and pair it up with a lot of water.

Do not go higher if feeling symptoms

If you are feeling symptoms the only real cure all is to go down to a lower altitude. With that said, the inverse is true. If you are feeling symptoms, the worst thing you can do is go higher in altitude. This can be a difficult decision when hiking or whatever. Like I have mentioned countless times before, sunk cost fallacy is real and everyone is susceptible. When you are on a long-planned trip and a couple miles from a summit it is easy to think you have to keep going. At this point it is a risk vs reward scenario. You risk getting to the top where your symptoms become crippling, and the situation turns for the worst.

Do know when to see a doctor

It is self-explanatory when to seek help for altitude sickness, but it is often ignored. It is rare to get HAPE or HACE from altitude, but it can happen. If your mild symptoms linger or turn to moderate or sever symptoms it is time to seek a professional. This can be a sign of something more serious than acute mountain sickness. Generally, symptoms take 12 hours to 4 days to go away. If your symptoms stay any longer or you have a bad feeling about them go to a doctor.

Getting acclimated is a gradual process. It takes two to four months to become fully acclimated. The cadets at the United States Air Force Academy, which ranges from 6,000 feet to over 9,000 feet, do not participate in physical training until the two-month mark when they are acclimated. Two to four months sounds like a long time and can be a little discouraging when planning a week or weekend trip. Do not worry though, altitude sickness does not affect everyone, and the fatigue felt from being unacclimated lessens quickly. Also, this is in reference to not feeling instant fatigue when exercising. To get acclimated enough to not experience symptoms while at rest takes one to three days. When trying to get acclimated again my self and other Coloradans try not to overly exert ourselves for the first two weeks. After the first two weeks we can handle most of the challenges in the area. At the two weeks mark I only experience altitude sickness symptoms at tree line, 11,500 feet and above. After a month or so I get about as acclimated as I can notice.

Altitude sickness generally lasts 12 hours to 3 days. In some cases, it will last four days. Most people, with rest and action taken, will get over their symptoms in 24 hours. If symptoms worsen or last longer than 3 to 4 days, it is highly recommended to seek help. This could be a sign of a deeper problem like HAPE or HACE.

Being at altitude is considered to be at an elevation over 4,000 feet. High altitude is considered 8,000 feet to 12,000 feet. Very high altitude is 12,000 feet to 18,000 feet. Extremely high altitude is over 18,000 feet. For reference Denver is at 5,280 feet, Colorado Springs is at 6,000 feet, and Alma, CO is at 10,361 feet. Ski slopes vary but on average are at about 11,000 feet while some go to 12,000 feet. Even if you are not hiking a 14,000-foot mountain in Colorado you can still be at high or extremely high altitudes.

Altitude sickness can start in at 5,000, although it is not too common. The higher up in altitude you go the more likely you are to get altitude sickness. That said, I know plenty of people that fly in and immediately hit the ski slopes at 11,000+ feet. It does not affect everyone, but the higher you go the quicker the bigger the chance you get altitude sickness.

I can not find any exact numbers to back up this section, so I will leave out quantifiable values. From my experience and experience of other Coloradans losing acclimatization is very quick. One of my hiking partners gets sent all over for business trips. He will be gone for 3 to 5 days and he will have almost completely lost his acclimatization. It is noticeable too, hikes that he could do no problem turn into a struggle. It is not just him either, I can attest to this claim and many other of my friends. Online, there are forums where people say they became unacclimated after 3 weeks or 2 months, but the point is no matter how long you spend getting acclimated it is easy to lose. I do not have verifiable numbers, but the general consensus is it is easy to lose.