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High Altitude: How Our Bodies Adapt

Whether you’re climbing a fourteener or just visiting the Mile High City for a week of recreational fun, one thing is for certain — both locations are a lot higher than sea level. But what’s the magic number that dictates when you’ve reached a high altitude? 

The sweet spot is anywhere between 4,900 to 11,500 feet. If you go higher, you’ve reached the even more elusive (and slightly less oxygenated) very high altitude. So, while you’re sipping that CBD-infused latte in downtown Denver, it may not look or even feel like you’re on top of the world. But if you’ve only just arrived, we’re willing to bet that you might notice one or two of the side effects of being in a high-altitude location, like dizziness, headaches or nausea. 

So why do we face these occasional uncomfortable symptoms and how do our bodies adapt to such a drastic change in height? In this article, we’ll break down how we acclimate to high altitude, what altitude sickness is and how to prepare for your next high-elevation getaway. 

Living the High Life: How Your Body Adapts 

When you arrive at a high-altitude location, it would be wonderful if you could snap your fingers and bam — instantly adjust your body to its new environment. Unfortunately, there’s more to it than that. The higher the altitude, the fewer oxygen molecules are in the air. This means that as you inhale, you’re receiving less oxygen than you normally would, which could lower your oxygen saturation levels. 

When your oxygen saturation lowers, your blood contains less oxygen. If this happens, your body may find delivering oxygen to your organs more difficult. To counteract this, your body produces more red blood cells, making it easier to pump oxygen through your system. 

Other short-term adjustments your body makes to acclimate itself include: 

  • Increased breathing rate
    The peripheral chemoreceptors in your body will detect a change in lower oxygen levels. When this happens, you may need to take more breaths so you receive the same amount of oxygen you would receive at a lower altitude. 
  • A faster heart rate
    Those very same peripheral chemoreceptors also cause stimulation to your sympathetic nervous system (SNS). The SNS responds to stressful situations, such as when your body realizes it needs to work a little harder to retrieve oxygen. In response, your heart rate may increase to deliver more oxygen-filled blood to your body. 
  • Increased urination
    When you’re at a high altitude, you’re more susceptible to alkalosis, a condition that occurs when there’s an imbalance in your body’s pH levels. Alkalosis happens when you have too many bicarbonates (a base) and not enough acids in your system. To avoid this condition, your body compensates by removing those bicarbonates through the kidneys and, eventually, through urination. 

What Is Altitude Sickness — and Can You Avoid It? 

As your body adapts to its new environment, you may experience altitude sickness, a term that describes several symptoms that can occur at a high altitude. Common symptoms of altitude sickness include: 

  • Headache 
  • Muscle aches 
  • Nausea 
  • Dizziness 
  • Fatigue 
  • Shortness of breath 
  • Loss of appetite 

While the symptoms may not sound (or feel) pleasant, they usually arrive within 12 to 24 hours after you’ve arrived at a high-altitude location and disappear after a day or two after you’ve acclimated. The good news is that not everyone will experience altitude sickness; if you do, you’ll likely only experience a few symptoms. 

How to Prepare for High Altitude 

Thankfully, there are a few preventative measures you can take to lessen your chances of experiencing altitude sickness, including: 

  • Staying hydrated 
    As your kidneys filter out the bicarbonates, you might find yourself taking a few extra trips to the bathroom. Since your body is losing liquid rapidly, it’s essential to drink plenty of liquids to keep yourself hydrated. 
  • Limiting your alcohol intake 
    You might be thinking, fabulousa cocktail is the perfect liquid solution. Not so fast. As your body adapts to the altitude, it’s not as equipped to process alcohol effectively. In addition, alcohol is a diuretic, so it will increase the number of times you urinate. 
  • Taking it easy 
    Your internal processes are doing a lot of work to help you adjust to the heightened elevation quickly. The best way you can help yourself is to relax as it adapts. You don’t have to lay in your hotel bed all day, but if you do decide to go for a hike or even a walk down Main Street, be sure to take it slow. 

Take Your Career to New Heights at the University of Florida 

If you’re taking a gap year to experience the world and take a breath of fresh (albeit less oxygenated) air in a high-altitude environment, we have the perfect way to help you prepare for the next phase of life. Whether you’re prepping for the MCAT or assembling an application to medical or nursing school, the University of Florida offers a Graduate Certificate in Medical Physiology that you can complete from almost anywhere — entirely online. 

While only 9 credit hours are required for completion, you can take up to 14 credits and explore electives that suit your interests and professional goals. Courses can be completed at your convenience and give you all the tools you need to prepare for the next chapter in your career, whether you’re going into dentistry, nursing, or another field in the medical industry. 

Apply now to study medical physiology at the University of Florida. 

Sources: 

https://www.ncbi.nlm.nih.gov/books/NBK539701/
https://med.libretexts.org/Bookshelves/Anatomy_and_Physiology/Anatomy_and_Physiology_(Boundless)/21%3A_Respiratory_System/21.11%3A_Respiratory_Adjustments/21.11B%3A_Adjustments_at_High_Altitude
https://pubmed.ncbi.nlm.nih.gov/14660497/
https://my.clevelandclinic.org/health/body/23262-sympathetic-nervous-system-sns-fight-or-flight
https://www.webmd.com/a-to-z-guides/altitude-sickness