Although this may not be the answer you were hoping for, I am not aware of an exception for illness or medical reason. As is stated in the California Code of Civil procedure:
West's Annotated California Codes
Code of Civil Procedure (Refs & Annos)
Part 2. Of Civil Actions (Refs & Annos)
Title 2. Of the Time of Commencing Civil Actions (Refs & Annos)
Chapter 1. The Time of Commencing Actions in General
West's Ann.Cal.C.C.P. § 312
§ 312. General limitations; special cases
Civil actions, without exception, can only be commenced within the periods prescribed in this title, after the cause of action
shall have accrued, unless where, in special cases, a different limitation is prescribed by statute.
I hope that this has served to answer your question. When rating my response, please rember that my job is to give you accurate information, even if the law might not be in your favor.