Five Effects of High Altitude on Your Body

From Bartlett’s Health on March 1, 2014

By Jennifer Gilligan 

Oxygen levels fall as altitude rises. This inverse relationship has all sorts of effects on the body. If you’re planning on moving or traveling to an area with a significantly higher elevation than you’re used to, plan ahead to minimize these five altitude-related conditions:

  1. Respiratory stress
  2. Dehydration
  3. Low energy
  4. Altitude sickness
  5. Difficulty sleeping

These five are them most common effects of high altitude (6,500 feet above sea level — or higher). Let’s take a closer look at them, what they can do to your body, and what you can do about them.

Respiratory Stress

One of the first things people realize when they’re at higher altitudes is that their breathing becomes faster and deeper. This happens because there’s less oxygen available in the air, so the body tries to compensate by taking in more air. People usually experience a shortness of breath for a couple of days, or even weeks, before they have acclimated by producing more red blood cells to capture additional oxygen from the air.

If you’ve ever traveled to a higher elevation, you’ve probably noticed feeling light headed when you stand up or exert yourself. This slightly uncomfortable feeling happens because your body is not accustomed to a low-oxygen environment. This relatively minor symptom of respiratory stress usually goes away with time.

In Colorado, for example, you can drive to the top of Pike’s Peak or Mt. Evans, both of which are over 14,000 feet. Just walking around once you get out of the car is enough to make you feel a little woozy.

This respiratory stress is amplified at extreme altitude (above 26,000 feet). No matter how long you try to rest and recover at this altitude, the human body does not have the capacity to function for extended periods without sufficient oxygen. Your body simply cannot take in enough oxygen at this altitude; the respiratory stress is too great. This elevation is referred to as “the death zone” because of more than 240 documented cases of mountain climbers dying because they pushed their body’s limits too far and ended up losing consciousness.


People also experience dehydration at high altitudes because of the low humidity. The combination of dehydration and lower oxygen levels makes it harder for the body to retain moisture. In addition, people perspire and urinate more at altitude, further complicating the problem.

People transitioning to higher elevations need to drink more water, approximately a gallon of water for the first 2-10 days, or at least a liter more water than you normally drink. It is also important and watch out for symptoms of dehydration such as dark urine; persistent dry mouth; swelling in the face, hands, and feet; as well as dry skin and itchy eyes. Also, using lotion will help the skin retain its moisture.

Avoid drinking coffee, tea, or alcohol — all of which are diuretics, which make altitude-related dehydration worse.

According to Dr. Jaroslav Boublik, Ph.D., the Scientific Director of AquaConneXions Pty. Ltd, altitude-related dehydration begins with thirst, followed by reduced appetite, skin flushing, dry mouth, fatigue, headache, chills, and dizziness. Approximately 20 percent of people will experience some of these dehydration symptoms during altitude acclimation.

Low Energy Levels

Because it’s harder for the body to get oxygen at higher altitudes (8,000 feet or above), people often feel lethargic until their bodies acclimatize. This process can take anywhere from a couple of days to six months. If the change in elevation is less than 8,000 feet, however, it may only take a couple of weeks before your body feels completely normal.

It’s interesting to note that people who live in very high altitudes, such as Ethiopia and Tibet, develop larger lung capacities to cope with the lower oxygen levels. Ethiopians who live in higher altitudes have approximately 25 percent more lung capacity than those of us who live closer to sea level. According to a 2006 article in High Altitude Medicine & Biology, compared to lowlanders, Tibetans from the Himalayan Plateau maintain higher arterial oxygen saturation at rest and during exercise and show less loss of aerobic performance with increasing altitude. Tibetans also have larger lungs, better lung function, and greater lung diffusing capacity than lowlanders.

Many athletes like to train at higher altitudes. High-altitude training strengthens their cardiovascular system and improves their endurance. It also helps athletes acclimate faster for competitions at altitude. Olympians are famous for using this sort of training regimen. Because the concentration of oxygen in the air is lower, training at higher altitudes forces the body to produce additional red blood cells to capture sufficient oxygen for high-intensity athletic performance. Having more red blood cells also helps athletes compete at lower altitudes because the body can absorb and move greater concentrations oxygen through the circulatory system to the muscles that are doing the work.

Nausea and Vomiting

Two in ten people experience true altitude sickness when they visit higher elevations. The most common symptoms are headaches, body aches, nausea, and vomiting. Additionally, some people are just more susceptible to altitude sickness than others; it doesn’t necessarily have anything to do with age or physical condition. A drop in oxygen availability combined with the body’s ability to perform physical activities in a low-oxygen environment cause Acute Mountain Sickness (AMS). AMS feels like a combination of the flu and a hangover.

Doctors can prescribe the drug Acetazolamide (Diamox) to help people cope with nausea and vomiting symptoms associated with altitude sickness. Regardless where you are when AMS strikes, I recommend using to locate a physician, get the proper medication, as well as some professional advice on how to cope with higher altitudes.  If your symptoms persist for a month or more, definitely find a physician to help you with your condition.

Difficulty Sleeping

Another problem many people experience at higher altitude is insomnia. The sleep center of the brain, (preoptic area of the anterior hypothalamus), is directly affected by low-oxygen levels. This is why it is more difficult to slip into REM sleep in a low-oxygen environment. People who aren’t used to sleeping at altitude have trouble getting to sleep and staying asleep. This problem almost always improves or disappears after a few weeks.

People who have difficulty sleeping at higher elevations may find relief from herbal remedies such as melatonin, valerian root, hops, and passion flower. Melatonin is a naturally occurring hormone that tells the body it’s time to sleep. It can be purchased over the counter at many stores, but make sure you take the right dosage; too much melatonin can produce insomnia. Valerian root is thought to affect the GABA production and absorption in the brain. This herb should only be used when you are ready to sleep, as it may cause immediate drowsiness. Hops are the key ingredient in beer that helps calm major stress areas within the brain. Passion flower works like an all-natural benzodiazepine. It releases chemicals in the brain that can reduce muscle spasms and aid in sleeping.

It’s also helpful to go to bed earlier to maximize the amount of sleep possible.

These five conditions represent the most common effects that higher altitudes have on the body. However, everyone’s experience is a little different, so the next time you’re planning to visit higher elevations, plan ahead and pay attention to what your body tells you.

Here are five common-sense tips when moving or traveling to higher elevations:

  1. Drink plenty of water (eight cups per day minimum).
  2. Avoid alcoholic and caffeinated beverages (alcohol and caffeine are diuretics).
  3. Go to bed early if possible and allow for mid-day naps to catch up on your sleep.
  4. If you are traveling from sea level to more than 8,000 feet, break up the trip by spending a day at an intermediate elevation (if possible) so your body can adjust gradually to the lack of oxygen.
  5. Don’t overexert yourself. Make sure to take your trek slowly. If you’re camping, make sure your base camp is at a lower elevation than where you go hiking.

Have you ever experienced any of these high altitude conditions? Do you have a sure-fire altitude sickness remedy? Please leave a comment below and tell us know.

Leave a Reply

Your email address will not be published. Required fields are marked *