big, huge, major
minor
emotional

have
We had our first major upset when Rogers was taken off with a leg injury.

cause

badly, deeply, really, terribly
easily
She was sensitive and easily upset.

not mean to, not want to, not wish to (formal)
I'm sorry—I didn't mean to upset you.
Keep the volume down—we don't want to upset the people next door!

be likely to
This decision is likely to upset a lot of people.

Upset is used with these nouns as the object:
arrangement, balance, status quo

appear, be, feel, look, seem, sound
become, get
Don't get so upset about it!

remain
leave sb, make sb
The incident had left him visibly angry and upset.

extremely, fairly, very, etc.
deeply, desperately (esp. BrE), greatly, particularly, seriously, terribly
She's obviously deeply upset by his comments.

genuinely, truly
thoroughly
a little, slightly, etc.
clearly, obviously, visibly
understandably
emotionally

about
She was still upset about her divorce.

at
He was upset at missing all the excitement.

with
I think she may be a little upset with you.

Upset is used with these nouns:
stomach, tummy, victory, win