take a turn for the better
Improve, as in We thought she was on her deathbed but now she's taken a turn for the better. The antonym is take a turn for the worse, meaning “get worse, deteriorate,” as in Unemployment has been fairly low lately, but now the economy's taken a turn for the worse. This idiom employs turn in the sense of “a reversal,” a usage dating from about 1600.
Words nearby take a turn for the better
take a rain check,
take a shellacking,
take a shine to,
take a spill,
take a stand,
take a turn for the better,
take a walk,
take a whack at,
take aback,
take account of,
take advantage of