The Italian word nervoso doesn’t mean nervous when describing someone’s behavior. It can mean:
tense
edgy
irritable
crotchety
If an Italian asks why you are nervoso/a, it doesn’t mean you’re nervous but it is likely that you are tense and edgy.
Quando Marianna ritorna a casa dopo il lavoro, rimane sempre nervosa e distratta; pensiamo che abbia un capo difficile, ma non ci si lamenta mai.
When Marianna gets home from work, she’s always irritable and distracted; we think she has a difficult supervisor, but she never complains to us.
The word ansioso means:
nervous
anxious
worried
Here’s another example using the adjective ansioso:
I nostri figli sono andati a Roma da soli per la prima volta in treno, e sono ansiosa mentre mio marito dice che mi preoccupo per niente. So che sono arrivati; perché non mi hanno ancora inviato un sms?
Our children went to Rome by themselves for the first time on the train, and I’m anxious while my husband says I am worrying for nothing. I know they arrived; why haven’t they sent me an sms yet?