The 22-year-old singer had at least five scheduled shows in December, including gigs in New York, Washington DC, and Atlanta.
"I am not feeling any better and after leaving the doctor today, I have been put on a strict vocal rest for the next two weeks. This absolutely kills me because I was so excited to see all of you on the road.
"I'm going to go home and rest so I can get back to see you all as soon as I can. I love you so much and am so appreciative of your love and support that you constantly show me. You mean everything to me," Trainor wrote in an Instagram post.