How Do High Altitudes Affect People with Asthma?

Health Professional

So what is the effect on high altitudes on asthma? If I board an airplane, will this make my asthma worse? What if you climb to the top of a mountain?

These are common questions I've had to answer over the years. In fact, when I traveled to Denver in 1985 to stay at the asthma hospital -- Denver is a mile high -- this was one of the questions my parents asked.

If high altitudes affect your asthma, it's due to one of the following:

  • Air is cooler and drier at higher altitudes. As I noted in this post, cool and dry air has in increased tendency to trigger asthma.
  • The higher up you go the less oxygen there is in the air you breathe, this results in less oxygen getting to your lungs. If your lungs are already compromised, and the oxygen in your blood is already low, going  UP may cause you to feel especially winded.

If your asthma is controlled, you should have no trouble coping with higher altitudes.   However, if you have uncontrolled asthma, or if you have severe asthma, you might have some trouble.

The folks with the most trouble coping are those with severe, persistent asthma, or your prototypical hardluck asthmatic.   The reason is because due to bad asthma, these folks might already have a lower level of oxygen in their blood.

When these hardluckers board a plane, or climb a mountain, they might start to feel winded before other folks do.   With a lower level of oxygen in their blood, and now inhaling less oxygen than at sea level, you can see how they might quickly get winded.

This is also true of Chronic Obstructive Pulmonary Disease (COPD) patients.   If you want to learn more about the details of why this happens, I explain it in this post about why COPD patients may experience dyspnea in flights.

An interesting twist here is that while doing my research I found many studies  (like this  2008 study) that actually show  higher altitudes may benefit asthmatics by improving lung function and reducing the need for asthma controller medicines.

The reason is believed to have something to do with a reduction of t-helper and b-helper cells that cause inflammation (swelling) in your airways. With less swelling your lungs are less responsive to your asthma triggers, and you'll require less controller medicine.

Likewise, this 2001 study  shows  children who live in higher altitudes were less likely to have asthma and when they did it was less severe.

Now these are just a few isolated studies, yet it's still interesting to think about.

If you have  hardluck asthma you might want to talk to airline officials about making plans to help you during flight.   Yet the rest of us asthmatics should be able to cope to higher altitudes quite well.