The 27-year-old singer said she often breaks into tears while recording a song, reported E!Online.
"In order for me to feel confident with one of my songs it has to really move me. It's when I start crying. It's when I just break out in (expletive) tears in the vocal booth or in the studio, and I'll need a moment to myself," she said.
The "Hello" hitmaker confessed that she was not sure about getting back into the music scene after 21's major success.
Her latest work is about the sense of longing for reconciliation and a genuine bond.
Her upcoming third studio album, 25, is set for release on November 20.