Demi Lovato's new tattoo is a reminder of her overcoming ''difficult things'' in her life.

The 'Heart Attack' singer - who entered rehab in 2010 to be treated for an eating disorder, self-harming and bipolar disorder - inked the phrase ''now I'm a warrior'' on her back earlier this week and she has revealed the new body art, which was inspired by the lyrics of a song on her new album, is an expression of the strides she has made in her life.

Appearing on talk show 'Late Night with Jimmy Fallon', she explained: ''It was kinda like a tribute to releasing an album, as well as overcoming some really, really difficult things in my life.

''I have a song on my album called 'Warrior,' and it's very, very meaningful to me. It's really heavy, the lyrics, but it's an inspirational song as well ... It's a negative thing turned positive. This is a song that was really difficult for me to write, record and now release.''

On the track, Demi sings about feeling ''shame'', having ''scars'' and developing ''thicker skin''.

Now in a better place, the 20-year-old star has also opened up about her relationship with fellow actress-and-singer Selena Gomez, 20, saying the former pals have repaired their friendship.

She told MTV News: ''We've been through a lot together. We've had periods of times when we grew apart and we just didn't really talk.

''But now we're in a place where we realise that life is so short, and that when you have people in your life that love you so much, then you should just always be around them.''