expression, godan verb (-su)
worry oneself over; be troubled by
Used when someone is mentally burdened or preoccupied by a concern. Often appears in the form 心を煩わす.
彼は将来のことで心を煩わしている。
He is worrying himself over the future.
そんな小さなことで心を煩わすな。
Don't trouble yourself over such a small thing.