The star was first diagnosed with myalgic encephalomyelitis (Me) when she was in a violent relationship in her teens, but the symptoms, which include extreme exhaustion and headaches, disappeared as she entered her 20s.
However, after shooting long hours on her chat show, which featured in-depth discussions with the likes of Lady Gaga and Gwyneth Paltrow, the autoimmune illness came back with a vengeance.
She tells Britain's You magazine, "I had no symptoms of it for about 15 years and then it came back right after we finished making The Conversation. I suffered from exhaustion, memory loss, dizziness, fever and swollen glands. There's only a small team of us on the show and I think we worked so hard that I was worn down."