High Altitudes: Your Body’s Response

Human bodies adapt to the environment around them. Some adaptations take centuries of genetic modification. Our bodies must make short term changes in some situations. When exposed to a different environment, quick acclimatization may be necessary for survival. High altitude areas force the body to make significant changes concerning oxygen intake and use.

The Environment

In places like Tibet and the Andes mountains, air is much thinner than what most humans are used to. The air at high altitudes is less dense, however, the percentage of oxygen per molecule does not change. The particles are further apart. This decreased density occurs because there is less air above it to add weight.  When you breathe in the air while in a high altitude, less oxygen is available per breath.

Immediate Response

Proper functioning cannot occur with smaller amounts of oxygen. Immediately, your body starts to respond with actions meant to remedy the situation. Heart rate increases as more breaths per minute are taken to achieve a sufficient oxygen supply. This contributes to a feeling of weakness or inability to exert physical energy. In an act of survival, blood circulation becomes focused on major organs first.


When your body does not receive the usual amount of oxygen each time you breathe in, complications can occur. The most common form of illness is called altitude sickness. Pulmonary or cerebral edema can also result. Altitude sickness stems from the rerouting of the blood flow. Headaches and nausea are symptoms that take place when extra blood is pumped to the head and diverted from the digestive system.

Pulmonary edema is a condition where fluid fills the lungs. This traumatic illness is a result of poor adjustment to a higher altitude. The body tries to acclimatize, but is not successful in some cases. Oxygen must go in while carbon dioxide is released. This gas exchange rate needs to stay balanced to avoid edema. The symptoms for this are much more severe than regular altitude sickness. Coughing, tightness of the chest, and difficulty breathing are some of the symptoms to look out for.

Cerebral edema refers to fluid and swelling around the brain. The symptoms are similar to simple altitude sickness. Nausea and weakness are common during normal acclimatization, but can also be signs of cerebral edema. The patient may also be lethargic and experience confusion. These extreme reactions can be fatal and must be treated quickly.


Trips to high altitudes should be planned carefully. Your body needs time to adjust. It is best to plan on participating in low key activities the first few days. Physical strain may not be tolerated well. Alcohol and caffeine will affect you differently in higher altitudes. These items should be avoided at first. Extra travel days should be allowed for ascending and descending. Prepare to spend a few days at various altitudes until you reach the highest point of your trip. Medication is available for those who have difficulty adjusting and for faster ascension. A trip to your doctor for a checkup prior to travel can help determine your needs.

The most dangerous issues arise at about 8,000 feet elevation. Spending the night at this height immediately after leaving a lower area can be especially dangerous. Many tourists opt to visit higher points during the day and sleep in a lower altitude. This can ease the stress on your body. Refrain from ascending further if your system is not responding well to the elevation at any point. Descend immediately if symptoms become severe or there is no improvement at any given elevation.


Acclimatization is the full physical adjustment to the change in altitude. At this point, your body feels more like normal and energy is regained. It can take several weeks to reach a full acclimatization. Increased production of red blood cells helps to offset the lower levels of oxygen. Athletes suffer a decline in speed and performance even after acclimatization. The human body is at a more natural state at lower levels.

The human body has a way of changing to meet different environmental circumstances. High altitudes elicit a big response in the way oxygen is distributed in the blood. The proper gas exchanges must be carried out repeatedly to maintain comfort and health. Proper preparations for travel can help to ease the transition to a higher elevation. Symptoms should be monitored for severity and longevity for safety purposes. Acclimatization is the goal that can be reached over time in a high altitude.

Do you have any tips for dealing with high altitudes? Let us know, below!


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