for the worse
turn for the worse
take a turn for the worse
For something that is worse or not as good, with a worse result.
He bought a new car but it turned out to be for the worse.
The sick man's condition changed for the worse.
take a turn for the better
To start improving; start to get better.
Aunt Hermione was very ill for a long time, but last week she suddenly took a turn for the better.
take a turn
To become different; change.
Mary's fever suddenly took a bad turn.
The story took an odd turn.
Often used with for the better or for the worse.
In the afternoon the weather took a turn for the better.
Suddenly the battle took a turn for the worse.