Los Angeles - Demi Lovato has a respiratory infection.
The 21-year-old singer was forced to seek medical help on Tuesday after she began coughing up blood just before she took to the stage in New York for her Neon Lights tour.
The Heart Attack hitmaker posted a screen shot on her Twitter account of a text conversation between her and a friend, where she revealed she had been spitting blood.
However, after her fans became increasingly worried about her health, she wrote: "For all of you that are worried, I saw a doctor and it's just a respiratory infection."
Earlier in the day, Demi took to Twitter to announce that she was feeling sick, but she was determined not to cancel her show.
She wrote: "The last thing I would EVER want to do is cancel a show, with that being said I'm super sick tonight so it may not be my best show BUT I'm SO excited to perform for you guys but I may need you to sing most of the show for me!!! Hahaha (sic)".
Despite battling with the illness, the concert in Long Island appeared to be a success.
She tweeted after the show: "I love you guys so much!!!! Thank you Long Island for an incredible night.. Soooo fun even when I'm sick!!! #NEONLIGHTSTOUR (sic)".