Jess Glynne "rarely" gets drunk.
The 26-year-old singer doesn't often indulge in alcohol because she thinks it is bad for her voice so feels the effects much worse when she does have a drink.
During a recent interview, she admitted: "I'm hungover [today]. It's quite a big one because I rarely drink. I have to look after my voice."
The 'Rather Be' hitmaker may not drink often now, but when she was 21, she regularly overindulged and didn't treat people well, though she has now learned from her mistakes.
She said: "I had a weird year when I was 21, and did some stupid things, drank a lot and treated my friends badly. It was a big year of learning."
Despite her fame and success, Jess hates being in the spotlight and feels uncomfortable when she gets recognised.
She told Grazia magazine: "I get so embarrassed if people recognise me, or if I'm in a shop and one of my songs comes on.
"I go red really easily. I think it's a ginger thing."
Meanwhile, one of the 'Right Here' singer's biggest regrets is the outfit she wore to the 2014 MTV Europe Music Awards (EMAs).
She admitted: "[I hate] all the photos of me at the EMAs in 2014. I looked like a joke.
"I hate my outfit, my hair... the fact my belly button was on show makes me feel sick."