Why the body has trouble functioning at higher altitudes

People who visit high altitudes, like mountain climbers or anyone who visits Denver, may know a little something about altitude sickness.

Altitude sickness occurs when there is lower oxygen pressure present and can result in shortness of breath, headache, and a fast heartbeat.

Part of the reason that being at higher altitudes can be problematic is because it reduces blood flow from the heart, but why exactly this occurs had been a mystery.

Now, a new study may have uncovered why the heart is unable to pump as much blood as it normally would to the rest of the body at higher altitudes.

The study was conducted by researchers from the Cardiff Metropolitan University and published in the Journal of Physiology.

For the study, researchers measured cardiac functioning at higher altitudes for two weeks at a research facility on White Mountain in California.

The results showed that there were two factors influencing the reduced blood flow from the heart at higher levels. The lower amount of oxygen in the air decreases the volume of blood circulating around the body and increases blood pressure.

However, while both of these factors impact blood flow, the researchers found that surprisingly reduced blood flow from the heart doesn’t impact the body’s ability to exercise to its fullest extent.

There are some limitations to the study as the number of participants who had their cardiac and pulmonary vascular functions measured via echocardiography was small.

The research does however provide an explanation for the reduction in blood flow from the heart with changes in oxygen pressure and could help with making higher altitudes safer for tourists, explorers, and people who live in mountain regions.

Next, the researchers will work on an expedition helping people in the Andean mountains deal with “Chronic Mountain Sickness.”

“Currently, a number of the research team are ready to depart for an expedition that will focus on high altitude natives who live and work in the industrial mines of the Andean mountains,” said Michael Stembridge. “Unfortunately, a third of these individuals experience long-term ill health due to their residence at high altitude, a condition termed ‘Chronic Mountain Sickness’. We hope to apply the findings of this work to help improve the health and well-being of these populations by furthering our understanding of the condition and exploring therapeutic targets.”

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By Kay Vandette, Earth.com Staff Writer