Singer Lily Allen has revealed that she has been diagnosed with a heart murmur.
Doctors discovered the condition at a routine check-up, Allen said
The 22-year-old pop star told Grazia magazine that she found out about the condition three months ago, after switching doctors.
Her recent sudden weight loss was a result of exercise following the health scare, she said - and not because she wanted to be "some skinny minnie".
A heart murmur is often harmless but can also indicate a hole in the heart or a heart valve problem.
The singer sparked concern when she shed 19lbs (8.6kg) and dropped from a UK size 12 to a size eight in just six weeks.
"When they asked me how much exercise I did, I had to be honest and say hardly any," she said.
"I used to love nothing more than sitting in front of the telly with two packets of Ginger Nuts and two bags of milk-bottle sweets - and I'd devour the lot."
"But this heart thing has made me cut back on all that kind of crap. I now find that, because I am looking after myself, I don't feel like eating the bad stuff so much," she said.
Allen said she now went to the gym three times a week and had a "hardcore routine" that lasted an hour and a half.
"I really want to stress that I haven't done this because I want to become some skinny minnie - I will never be like that," she said.
"I was going pretty crazy back in the summer, drinking way too much and partying loads. But now I don't want to drink so much, I've been cutting back.
"I should also give up smoking, but haven't quite managed that yet."
The singer recently landed a deal to present her own BBC Three TV show, based on the social-networking phenomenon that helped to launch her music career.