Has your doctor advised that you avoid high elevation? This is a common problem. The higher the elevation (or altitude) the less oxygen there is in the air. This leads to lower oxygen in the lungs and then lower oxygen in the pulmonary arteries. Unfortunately this causes constriction or tightening of the pulmonary arteries. As the pulmonary arteries constrict the right side of the heart has to work even harder to pump blood. Patients experience increased shortness of breath, fatigue and can even have fainting episodes. Patients often retain additional fluid while at higher elevation as well.
How high is too high?
There is no one number. The risk of increased symptoms and worsening of PAH increases with increasing elevation. For example, most patients can tolerate 3,000 feet but few patients with PAH do well at 7000 feet. If you use oxygen, you can reduce your symptoms by increasing the liter flow on your oxygen source. Minimizing exertion can also help. Most importantly, if you are feeling poorly, you should return to lower elevation.
When you travel on an airplane the cabin is pressurized to about 7500 feet of elevation. That means that for the bulk of the flight it is as though you were visiting a destination 7,500 feet above sea level. Most patients can tolerate this for a short flight such as 2 hours. Transcontinental flights can be more dangerous. You should always check with your doctor prior to flying. If you use oxygen you will have to have your doctor fill out forms in advance and you will need to have a TSA approved portable oxygen concentrator.