The 22-year-old singer released the song and its official video Thursday on her Vevo account. The clip finds Gomez crying as she sings about a troubled love.
"When I was on stage and I was thinking of... I felt like I know him, though," Gomez shares in the beginning of the clip. "I know that I know his heart and I know wouldn't do anything to hurt me. But I didn't realize that feeling so confident, and feeling so great about myself, and then it just be completely shattered. By one thing, by something so stupid. But then you make me feel crazy, you make me feel like it's my fault. I was in pain..."
"The Heart Wants What It Wants," is the first single from Gomez' upcoming compilation album, For You. The record will be the singer's first greatest hits album and will be released on Nov. 24.
Hours after the launch of her new single, Gomez thanked fans on Twitter for making it No. 1 on iTunes.