The 21-year-old singer has also postponed her upcoming two shows in Detroit and Chicago and has cancelled more dates on her "MTrainTour", as she is still dealing with her illness, reported AceShowbiz.
The singer announced the news in an Instagram post and gave fans an update on her condition.
"But there is good news! I'm feeling much better," Trainor wrote.
"Thank you Dr Kessler for seeing me immediately and being so helpful and thank you guys for all the edits/get well posts you made. You made me feel a lot better about this crappy situation. I love you all so much."
"Right now the doctors want me on complete vocal rest until they are healed. I have never missed a tour date before so this is killing me," she said in a statement last week.