HSK 4
Tā zǒngshì dānxīn yīxiē bù kěnéng fāshēng de shì, jiǎnzhí shì zìxún-fánnǎo.
He always worries about things that can't possibly happen - he's really just creating unnecessary trouble for himself.
HSK 7-9
Nǐ bù qù xiǎng nà jiàn shì jiù hǎo le, hébì zìxún-fánnǎo?
Just don't think about that matter - why bring trouble on yourself?