The 21-year-old singer has pulled out of Friday's show at Charlotte, North Carolina and both Saturday and Sunday's concerts in Atlanta, Georgia, but is hoping to be fighting fit for her performance in Montreal, Canada, on July 14.
'It breaks my heart to miss out on this weekend's shows with my friends in Charlotte and Atlanta,' Swift told PopEater. 'I would never cancel if I thought I was physically able to perform these shows. I am so sorry to the fans, but I look forward to seeing you when we come back through your towns, which we will do.'
She also had to bail out on Louisville, Kentucky, last week thanks to the same illness.
'Louisville, I so sorry to have to postpone this show to Oct. 11,' Swift posted on her Twitter page. 'This is my first time having to do this. I'm so, so sorry.'
The Charlotte date has been rescheduled for November 16, while the Atlanta shows will take place on October 1 & 2 and Louisville on October 11.