Mandeep R. Mehra, medical director of the Heart & Vascular Center at Brigham and Women’s Hospital in Boston, took a long look at Leonardo da Vinci’s masterpiece, “Mona Lisa,” while standing in line last summer at the Louvre. That was when he decided that the Italian noblewoman Lisa Gherardini, who the work is thought to be of, likely suffered from hypothyroidism.

“I had the chance to just stand there for an hour and a half staring at nothing but this painting,” Mehra tells Yasmin Tayag at Inverse, according to Smithsonian Magazine. “I’m not an artist. I don’t know how to appreciate art. But I do sure know how to make a clinical diagnosis.”