Kelly Clarkson "hit rock bottom" when her career took off following her American Idol win - because she worked non-stop for four years.
The Miss Independent hitmaker won the inaugural contest in 2002 and went on to release two albums by 2004.
Clarkson promoted the releases around the globe, but her packed schedule had a bad effect on her health and she took time out from the spotlight to recover.
And the 29 year old admits the years of working non-stop have aged her considerably.
She tells Britain's Closer magazine, "I feel like I'm 45. Because my career went from zero to 100, there was no 'growing'. I learnt well under pressure, but like, four years passed by and I hit rock bottom. It was four years of non-stop (work).
"(Second album) Breakaway just exploded everywhere. Everyone was making a lot of money, so everyone was pushing the train.
"That's when it finally all caught up with me. I came down with 'walking pneumonia' for the second time in a year. My body was physically giving up. I took six months off and went home. I love working, but at the end of the day you've got to take care of yourself."