Living on borrowed time
vivʁ syʁ dy tɑ̃ ɑ̃pʁœ̃te
In French Vivre sur du temps emprunté
This idiom is used in French to express that someone's life is hanging by a thread or that they are surviving against the odds.
Example
"Après sa maladie, il avait l'impression de vivre sur du temps emprunté."