The most common and most likely answer to this crossword clue is the 2 plus 1 plus 4 letter word IN A STEW
I've seen this crossword clue in The Daily Telegraph
I
N
A
S
T
E
W
More clues leading to the result IN A STEW
Buddy explains!

The straight part
We know that "Concerned and upset" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case concerned and upset = in a stew.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.