That's got to be the best way to find out the options. I think deferrments of up to a year are possible at a lot of schools and that asking for medical reason would be among the most likely to succeed.
Good Luck!
Edit: also found this which may be relevant (your profile says CA)
http://www.csun.edu/~govrel/ArchivesJuly-Dec00.htmlAB 1958 (Romero) UC, CSU: Deferred Enrollment
This bill would request the UC and require the CSU to allow any person who is admitted to full-time undergraduate status at any of their respective campuses to request a deferment of enrollment for up to one academic year.
In essence, this bill would allow an applicant who has been admitted to a UC or CSU campus to defer enrolling for a year while not losing his/her "place in line," and would also preclude the individual from having to go through the application process a second time.
The final version of the bill specifies that the deferment be granted on a case-by-case basis, within the discretion of the university, in response to criteria cited by the student, including, but not limited to any of the following: (1) financial need, (2) family commitment or obligation (especially a situation caused by the death or serious illness of a family member), (3) medical condition, and (4) the student's desire to enroll in a foreign study program that is offered at another institution of higher education. <2/25/00, 7/13/00, 8/25/00 Legislative Updates>
Status: APPROVED by the Governor on September 7.