Demand that you have your heart evaluated. For three years I begged my pulmonologist for supplemental oxygen when I would be exerting myself. I continually managed the 6 minute pO2 walk test without dipping below 92. A new pulmonary function test demonstrated that there was no further loss of lung function.

After a bad fall I experienced increased trouble breathing. I was admitted to the hospital where a series of tests were performed. It turned out I was experiencing heart failure and placed on a diuretic. Within a week I was breathing easier than I had in a couple of years.