Conversation so far:
When did Jerry lewis first fall ill?
Jerry Lewis revealed in the 2011 documentary Method to the Madness of Jerry Lewis, that he suffered his first heart attack at age 34 while filming Cinderfella in 1960.
What caused Jerry Lewis' illness?
Lewis suffered from a number of chronic health problems, related both to aging and a back injury.
How did Jerry Lewis hurt his back?
Lewis suffered from a number of chronic health problems related to a back injury sustained in a comedic pratfall.
Are there any other interesting aspects about Jerry Lewis' illness besides suffering from a number of chronic health problems related to a back injury sustained in a comedic pratfall?
Jerry Lewis' comedic fall has been stated as being either from performing on the Las Vegas Strip on March 20, 1965, or during an appearance on The Andy Williams Show.

Question: How did this illness affect him?
Self-contained rewrite: How did Jerry Lewis' illness affect him?