According to TMZ, Selena Gomez, 18, was rushed to the hospital following her appearance on "The Tonight Show" Thursday. The website, citing unnamed sources, says she was feeling “horrible” Thursday night both during and after the show. The Disney star was reportedly complaining of nausea and a severe headache.

Her rep tells CNN, "Last night after Selena's appearance on ‘The Tonight Show’ she wasn't feeling well and was taken to the hospital. She is currently undergoing routine tests."

Selena also canceled her performance at Santa Monica Place, an outdoor mall in L.A.