The Come and Get It star shared the secret with Billboard magazine readers last week (ends09Oct15), when she confessed the real reason behind the cancellation of her 2014 Australian tour. At the time, the singer/actress faced criticism for claiming she needed to "spend some time on myself in order to be the best person I can be" and she entered the Dawn at The Meadows treatment centre in Arizona to seek help.

She subsequently told the publication she needed to take the hiatus to undergo treatment for her autoimmune disease.

"I was diagnosed with lupus, and I've been through chemotherapy," she said. "That's what my break was really about. I could've had a stroke. I wanted so badly to say, 'You guys have no idea. I'm in chemotherapy. You're a**holes.' I locked myself away until I was confident and comfortable again."

Selena was asked about her condition on Monday (12Oct15), when she performed in New York City for U.S. breakfast show Today, but she was hesitant to go into detail about how she was feeling onstage.

"To be honest it still kinda makes me a little uncomfortable to talk about it," the 23 year old confessed, "but genuinely, I feel like (by speaking out about it) I'm able to reach my fans and understand people when I am one on one with them and they're dealing with the same thing because I've been there, so I'm just trying to take something that maybe is negative and turn it into a positive."