What is Altitude Sickness?

Altitude sickness is an ailment that strikes travelers who venture up into gorgeous mountain habitats, high above sea level. Those who have experienced altitude sickness, know that it is a very real, and terribly unpleasant condition, that if extreme, can be dangerous.

Air is Thinner at High Altitudes

The percentage of oxygen in the atmosphere is the same at both low and high altitudes. If this is the case, what causes altitude sickness? The issue is not the oxygen levels in the air, it is the pressure of the air in the atmosphere.

The higher you are above sea level, the lower the pressure in the atmosphere. This is referred to as “thin air.” What does this term actually mean? When you decrease pressure, there are fewer molecules, of all types, including oxygen, present. So thin air has less total oxygen for you to inhale than the more compressed air at sea level. This is the root cause of altitude sickness 1.

What is Altitude Sickness?

If you start to feel sick within a day (or sometimes two) of ascending to higher altitudes, you may have altitude sickness. Symptoms can be flu-like and in severe cases similar to a chest cold. When I’ve experienced it, I’ve had a wicked headache, vomiting, and aches throughout my entire body. These are just a couple of the symptoms of altitude sickness, which is also referred to as high altitude illness (HAI), and acute mountain sickness (AMS).

Altitude sickness is thought to strike men and women equally. Although experts argue that fitness does not play a role in it, I have found that the fitter I am, the better I acclimate to higher altitudes with less symptoms. High altitude is considered 8,000 feet and above, however, when coming from sea level, I have experienced it at as low as 5,000 feet.

A colleague of mine, Dr. Todd Dorfman, who works in the ER at Boulder Community Hospital, says that people coming from sea level start to compensate for the lack of oxygen by increasing their heart and respiratory rate immediately upon arriving at any increased altitude. True altitude sickness (HAI) usually does not occur until a minimum of 8,000 feet in healthy individuals, but underlying medical problems can make compensation more difficult at any altitude and increase the risk of HAI at lower altitudes.

Symptoms of Altitude Sickness

The symptoms of altitude sickness generally develop within a day of reaching high altitude. Symptoms will vary depending on the severity of your condition. Those experiencing a mild case may have:

  • Loss of Appetite
  • Nausea, Vomiting
  • Dizziness
  • Headache
  • Muscle Aches
  • Insomnia
  • Shortness of Breath
  • Rapid Heart Beat 2

Symptoms of more severe altitude sickness often include:

  • Coughing
  • Chest Congestion
  • Pale Complexion
  • Lack of Balance

Remember, altitude sickness can become serious, so if you feel very ill at high altitudes, see a doctor even if it means making a trip to the emergency room.

When we bought a second home in Vail, Colorado and began spending weekends there on a regular basis, HAI was something I became well acquainted with. Fortunately, I developed a number of strategies, and I no longer suffer from it.

In Health Tips for Altitude Sickness, I share my secrets for surviving and thriving at high altitude, and I offer you amazing ways to combat this annoyingly unpleasant condition!


61 responses to “What is Altitude Sickness?”

  1. Homeopathic coca helped me a lot when I moved from sea level to 7000 feet in 2004. I’d had a horrible time visiting the Andes in the 90s, so I wanted to be prepared. It’s over 10 years ago now, but I think I took my first dose about a month before the “ascent.” A homeopathic materia medica book should have directions. Your only problem could be procuring the homeopathic coca! I had a prescription and got it from a small homeopathic pharmacy.

  2. I’ve lived in several high altitude locations, including Taos, NM. Not sure if I can mention a brand name here, but the supplement called Cholorxygen is a very effective way to offset altitude sickness, or to prevent it altogether if you take it several days ahead of your trip. It is pure chlorophyll and adds oxygen to your red blood cells.

    High altitude regions often have oxygen “bars”; which are businesses where you can buy 15-minute increments of oxygen to inhale, again, to offset the effects of being a flatlander in a high altitude area. The effect is usually an immediate improvement. Check Yelp for oxygen bars if you are visiting a place like Denver, or any of the ski areas in the southwest.

  3. My husband experienced severe muscle cramps on his business trip to Denver the week before Christmas. He has to go again the end of this month so any strategies to overcome altitude sickness would be great!

  4. I developed HAI when I moved to Monument, CO in 2012. I had to use O2 full time
    because I could not acclimate and finally my Pulmonary MD said the best thing for me was to return to sea level.
    I did that but am anxious to know how you dealt with it so I can visit my family occasionally.
    Would appreciate this information, Elana.

  5. I have followed your posts for several years now. I enjoy your cookbooks! I live in Texas. My husband just transferred to Denver to work. We are keeping our residence in Texas. I experience nausea and fatigue when I visit him, as well as insomnia. I do have a prescription for Diamox which has helped. I am very interested in what works for you. I had a difficult time walking at Rocky Mountain National Park at the tundra level. I did experience rapid heartbeat and coughing upon returning to Denver which scared me. I do drink gallons of water when I’m there.

  6. Please share as I quit skiing which I used to love to do. I get it bad when I go to Teluride and not as bad at Mammoth but still hate knowing that I am making myself sick just to go skiing .

    • Hi,
      Just wanted to add a little to the conversation in regards to Mammoth.
      I do suffer from altitude sickness and I have since I was a kid. However, my sickness comes at much lower elevations. I am beginning to think I have some kind of underlying condition for reasons I will not get into here on this site. Anyhow, I live in California. When I travel by car to Mammoth, I always pull over just as the car begins to gain altitude above the town of Bishop. I just need to pull over(in a safe place, of course) for about 10 minutes or so and I start feeling much better. I find that I feel really good the rest of the trip. This may not be true for others, but it works like a charm for me and now apparently my one daughter. Also, I do this when traveling to other areas in California that have a climb and again I find that it works for us.

      • Liz, this is a fantastic strategy. It helps your body acclimate to the increase in altitude more slowly and effectively. My doctor and I have discussed this :-)

  7. Having had some episodes of altitude sickness, I welcome the protocol you have figured out! Altitude sickness is dreadful.

  8. Elana – Thrilled to learn you’ve found strategies for living at (not just visiting) higher altitudes! I never thought I could return to my beloved New Mexico because all my research on handling the altitude came up empty. Can hardly wait for your next article.
    Gratefully, Irene

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