a sigh of relief

A sigh of relief is when you suddenly feel very happy or relived that someone unpleasant is over or did not happen at all. This can true to for an even or a person being in your presence, such as an unpleasant person who has just left the room, and you suddenly feel that sigh of relief. The same can be said for a situation which you want to avoid and breathe a sigh of relief when it doesnt happen.