The most common and most likely answer to this crossword clue is the 7 letter word GRIEVES
I've seen this crossword clue in The Guardian
G
R
I
E
V
E
S
Buddy explains!

The straight part
We know that "is upset/is upset" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case is upset/is upset = grieves.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.
What does GRIEVES mean?
GRIEVES verb- To cause sorrow or distress to.
- To feel very sad about; to mourn; to sorrow for.
- To experience grief.
- To harm.
- To submit or file a grievance (about).
- A governor of a town or province.
- A manager or steward, e.g. of a farm.