Quitting due to health reasons

I turned in my resignation letter at my seasonal/part-time job.

The clerk asked me for a reason (there was a voluntary termination form) so I put “medical”, and now my supervisor wants to talk to me. Now I am worried that she would ask me what condition it is...

Am I legally required to disclose my condition? I live in California, US. If not, is it normal for bosses/employers to ask employees’ specific conditions?

usa jobs
usa jobs resume
usa hotel jobs
usajobs
usa jobs federal government
usa job in ksa
usa jobs
usa jobs login
usa jobs gov
usajobs.gov
www.usajobs.gov
usajobs.com
usajobs
usajobs.gov official