Sheryl Crow has tended to laugh off the onstage moments where she forgets lyrics, but it turns out her memory lapses were a sign of a serious medical issue. “I worried about my memory so much that I went and got an MRI,” she told the Las Vegas Review-Journal. “And I found out I have a brain tumor. And I was, like, ‘See? I knew there was something wrong.’”

Crow made the revelation during an interview with the paper on Friday. The diagnosis could have been a crushing blow for the singer, who has already survived breast cancer, but she clarified that her health is fine. “I haven’t really talked about it. In November, I found out I have a brain tumor. But it’s benign, so I don’t have to worry about it. But it gives me a fit.”

Watch Sheryl Crow Perform ‘Summer Day’ on ‘Live on Letterman’