9 Tips to Avoid Altitude Sickness While Hiking

Last updated on April 14th, 2021 at 05:21 pm

Altitude sickness is the term we’ve given to a range of uncomfortable, sometimes serious, symptoms. While there are many complexities to what cause altitude sickness there are really just two primary factors: altitude and time. Balancing the speed of elevation gain is the only way to avoid altitude sickness while hiking.

There are ways to help ease the symptoms of altitude sickness once symptoms have set in, but the goal should always be avoiding these symptoms altogether. We go into each of this much more later in the post, but here are 9 tips for avoiding or preventing altitude sickness while hiking:

Discuss altitude with your physician
State your goals for the hike
Pre-acclimatization
Acclimatization
Hike high and sleep low
Hydrate every day
Eat food, specifically carbs
Know what altitude you are used to
Acetazolamide preventative drug

The rest of this post provides intends to provide more detail on altitude sickness and how exactly you can avoid it while hiking.

Since altitude sickness can become serious please read through this entire post to better familiarize yourself with the different types of altitude sickness and the associated symptoms.

What Causes Altitude Sickness On a Hike

The first step in avoiding altitude sickness is knowing what causes it, and when you may be susceptible to experiencing common symptoms.

The Physiological Effects

According to the European Respiratory Review, a drop in barometric pressure is the defining environmental feature at high elevations. This drop in barometric pressure causes problems for our bodies oxygen transport system.

Our bodies often adapt to these changes in pressure through a series of helpful physiological changes, however, sometimes our bodies reactions are intolerable.

More specifically, our bodies react by developing hypobaric hypoxia, which in simple terms causes less oxygen to be available for muscles, organs, and our bodies in general. A fancier way to describe this experience is by saying the partial pressure of oxygen is reduced.

Hypobaric hypoxia is often the beginning physiological change we experience when taking on higher altitudes.

At What Elevations Are You Susceptible

Altitude sickness becomes a threat starting at 5,000 ft. or more. The risks increase at higher altitudes, and as ascents are made rapidly. If you ever plan to hike around mountains your efforts will likely take you higher than 5,000 ft. In other words, unless you plan to hike on only flat land, you are susceptible.

Considering there are about 45 peaks in the US greater than 14,000 ft. there are many popular hiking destinations where altitude sickness can take hold.

Types of Altitude Sickness and Symptoms

There are three primary types of altitude sickness with varying symptoms and severity. The range of symptoms is vast across the three types of altitude sickness. While it is uncommon, the most severe forms of altitude sickness can cause permanent damage, or death (rarely).

Acute Mountain Sickness (AMS)

AMS is the least serious and most common form of altitude sickness. Symptoms are nausea, headache, dizziness, and extreme fatigue. As is the case with nausea there may be an instance of vomiting, as well. This type of altitude sickness is often compared to the way you might feel when having a hangover.

High Altitude Pulmonary Edema (HAPE)

Low oxygen levels and barometric pressure will certainly have some effect on our body. Dizziness, nausea, and a headache may be common for all types of altitude sickness. With HAPE, however, the drastic impact on our respiratory system and blood flow is the serious threat.

Small pulmonary arteries may contract in the lower blood oxygen levels experienced in higher altitudes. This constriction may lead to capillary congestion and pulmonary edema.

Pulmonary edema, in simple terms, is when fluid fills the air spaces of the lungs. This can be fatal.

Coughing and a low fever may be additional symptoms to look out for.

High Altitude Cerebral Edema (HACE)

HACE can be fatal, and for this reason, any of the symptoms outlined here should be taken extremely seriously if experienced. While common symptoms such as headache and dizziness will persist, HACE brings with it much more serious symptoms.

Decreased consciousness and ataxia are a sign of something more serious occurring. Simply put, when experiencing ataxia, control of bodily movements and functions may be lost. These symptoms may be coupled with a noticeable discoloration of the skin due to lack of circulation.

Your body’s nervous system is being affected when experiencing these symptoms. This is serious.

Avoid Altitude Sickness While Hiking

As mentioned, altitude sickness can impact anyone. Whether fit or not, young or old, hiking at high altitudes can affect you. Since our bodies are very adaptable the goal should be to give the time to do what they do best: adapt.

1. Discuss Altitude With Your Physician

Seems common sense, but many people skip a doctors visit before a big trek. Don’t be that person, and recognize that a physician may a better understanding of your specific medical conditions.

While it is great to have a basic understanding of avoiding altitude sickness on a hike we fully recommend consulting a physician.

2. State Your Goals for the Hike

It is important to state your goals for a hike because this will, in part, dictate your approach to the entire effort. Build in rest days, and mix them with days where chunks of altitude gain are made. If you are a flatlander and have never hiked a 14,000 ft. summit you should factor in additional time to make it to the top.

3. Pre-acclimatization

Pre-acclimatization involves a lot of advanced planning but may be one of the absolute best ways to avoid altitude sickness on a hike. One downside of this route is it requires a lot of time.

The goal is simple. Remain at a set elevation for an extended period of time before taking on elevation gains. Think about professional athletes that compete in higher altitudes. Often times they arrive a week or more in advance to get their bodies to adjust.

Depending on your available time it could be worth planning for additional days to get your body ready for the elevation gains to come.

4. Acclimatization

While pre-acclimatization is getting used to the elevation in advance, acclimatization should be thought of as adjusting on the go.

At the beginning of this post, we mention the speed of elevation gain as the real key to avoiding altitude sickness on a hike. Even if you are in the middle of your ascent, this theory holds true.

According to Dr. Andrew Taylor of the Emory University School of Medicine, “A rapid rate of ascent is an important contributor to the development of AMS (acute mountain sickness)…differences of a few days in acclimatization can have a significant impact on the prevalence of AMS, symptom severity, and mountaineering success.” (cited journal)

Avoid rapid elevation gains. Limit single day gains to around 1250 to 1750 ft. of elevation gain per day. Depending on your ultimate goals of the hike entertain the prospect of remaining at a particular elevation for an extra day.

Listening to your body is key.

5. Hike High Sleep Low

Part of “taking it slow” on high elevation treks is hiking high and resting low. Essentially, this is an extension of acclimatization.

As you make your way up steep hikes continue past where the final days camp will be set up. Hiking even 500 vertical feet higher than where you are sleeping is very helpful. Then, turn around and head back down the same distance to set up camp for the evening.

This allows for shock and rest.

In other words, your body gets the shock of a higher elevation, but it is only brief exposure. Sleeping at the slightly lower elevation ensures better sleep than you would otherwise get. Getting a good nights sleep will help you avoid altitude sickness while hiking.

The shock and rest approach is practiced by guides and experienced hikers alike.

6. Hydrate Every Day

Make sure you keep drinking water as you gain elevation. As a rule of thumb drink 3 to 5 quarts of water per day, regardless of temperature. This comes to about 1 gallon of water per day or about 4 liters per day.

Keep in mind that everyone is different. If you think more than a gallon of water a day is required, be sure to get what you need.

As elevation is gained temperature is sure to drop. Don’t let this stop you. Continue hydrating as necessary.

7. Eating Food (Carbs!)

You are working very hard to ascend to the summit of an awesome peak. Your muscles are working to push and pull you vertically, and this takes energy. A lot of energy. Carbohydrates can help.

Carbohydrates are specifically helpful in avoiding elevation sickness. Studies have shown that the digestion of carbs improves hemoglobin saturation, which helps battle AMS. While the digestion of consumed carbs can’t continue forever, the physiological relief provided is real.

Fighting the altitude changes should be your bodies main effort, keeping it fueled is the least you can do to help. Take the simple steps of providing the calories and nourishment required as a store of energy.

8. Know What Altitude You Are Used To

If you hike 14,000 ft. summits every other weekend, and you live around Denver, CO your body is likely more ready for altitude gain than most. This doesn’t mean you’re immune to the pressures of altitude, but it does mean your body has been quietly acclimating for a long time.

According to Dr. Andrew Taylor of the Emory University School of Medicine, where you live matters. If you live in an environment with a higher elevation your risk for developing AMS drop dramatically.

The opposite proved true from travelers originating at sea level. Those of us from flat lands will have a much greater chance of getting sick.

9. Acetazolamide (Preventative)

Acetazolamide is a carbonic anhydrase inhibitor. In other words, this is something you can take to reduce the risk of developing altitude sickness. While not a silver bullet the preventative drug is supported by the medical community as an effective preventative. If you are heading to a mountain range, and seek out your physician, it is very likely this can be prescribed.

Who is at Risk for Altitude Sickness

Everyone is different, and there is no certain way to tell which of us are more susceptible. The way each our of bodies react to changes in altitude vary. In other words, it doesn’t matter if you are old, young, fit, or out of shape. We are all at risk.

People of all walks of life experience altitude sickness on hikes. Only those who have acclimated to a high altitude environment have an assured decreased risk.

Don’t Let Altitude Stop You

Altitude can be a serious environmental shift for our bodies to adapt to. For most of us, however, this doesn’t mean we need to give up on hiking higher. Instead, the best option is to take our time in gaining elevation. With adequate time our bodies can adjust, and we will be able to continue higher.

It is definitely worth taking a bit more time in getting to the many peaks, crests, and vistas we dream about. This is specifically true when considering the two alternatives: 1) Get sick, or 2) stay at home.

In our opinion, neither of these are real options.

Instead, we recommend talking to your physician, taking it slow, and reaching as many peaks as possible.

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