The internet is full of pages and posts nuancing the difference between worry and concern. Worry is heart-felt, concern is cold; worry is a problem, concern is a solution; worry is a subset of concern. Some people think they are perfect synonyms.
My father used to say that he had few worries, but many concerns. He told me that to worry was unproductive, but to be concerned was healthy. I think he would have agreed with the idea that to worry is to focus on the problem, to be concerned is to focus on the solution.
Concern seems like a very human feeling, showing empathy or sympathy (another topic for a blog entry in the future.) It also seems to be reflective, suggesting a thoughtful process. Worry just appears to be easier, and less meaningful. Nobody wants to be labeled a worrywart!
So don’t worry, be concerned.