Ian Anderson, frontman and flute player for Jethro Tull, has revealed that he’s battling chronic obstructive pulmonary disease (COPD). “I’m going to tell you something I’ve never told anybody in public before,” Anderson told Dan Rather during a recent interview on his AXS TV series The Big Interview. “Since it’s you, I will choose this moment to say I am suffering from an incurable lung disease with which I was diagnosed a couple of years back.”

“And I do struggle,” Anderson continued. “I have what are called exacerbations, periods when I get an infection, it turns into severe bronchitis and I have maybe two or three weeks of really a tough job to go out there onstage and play. Fingers crossed, I’ve gone 18 months now without an exacerbation. I’m on medication. If I’m kept in a reasonably pollution-free environment in terms of air quality, I do okay.”

Although Anderson says that his “days are numbered,” the disease has not progressed to the point where it affects his day to day life: “I can still run for the bus.” And he lays some of the blame for his condition on spending “50 years of my life onstage amongst those wretched things that I call smoke machines.” The full interview airs tonight, 5/13 at 8PM ET; watch a clip from it below.