Taylor Swift has said that her mother Andrea has been diagnosed with a brain tumour while receiving treatment for another form of cancer. 

Andrea Swift was first diagnosed with cancer in 2015, with Taylor Swift revealing last year that her mother's cancer had returned for a second time.

In a new interview with entertainment trade publication Variety ahead of the release of her new documentary, Miss Americana, the singer said her mother has since been diagnosed with a brain tumour. 

"Everyone loves their mom; everyone's got an important mom," said Swift. "But for me, she's really the guiding force. Almost every decision I make, I talk to her about it first. So obviously it was a really big deal to ever speak about her illness."

"While she was going through treatment, they found a brain tumour," Swift continued. "And the symptoms of what a person goes through when they have a brain tumour is nothing like what we've ever been through with her cancer before. So it's just been a really hard time for us as a family."

Miss Americana will premiere at the Sundance Film Festival in the US on Thursday, January 23. It will be available on Netflix from Friday, January 31.

Swift will headline the Glastonbury festival in June. She is playing a number of festivals and four US dates as part of her touring plans.

"I feel like I haven't done festivals, really, since early in my career - they're fun and bring people together in a really cool way," she told Variety. "But I also wanted to be able to work as much as I can handle right now, with everything that's going on at home. And I wanted to figure out a way that I could do both those things."