do not lose sleep over it

• 不必担心；不因某事而睡不着觉

do not lose sleep over it的用法和样例：

例句

1. It's a pity that you didn't pass the exam, but I shan't lose any sleep over it, there are more important things to do.
   你没考及格真遗憾，不过，我不会为此担心，还有更重要的事情要做呢。