How should we react facing a disease? Should we fight against a disease? I mean, to seek for healthcare. Do diseases have a purpose?

I wonder How should we react facing a disease? Should we fight against a disease? I mean, to seek for healthcare.(Our body already do that) Do diseases have a purpose? Albert Einstein refused to get healthcare , although there were treatment options for his disease > When asked if he wanted to undergo surgery, Einstein refused, saying, > "I want to go when I want to go. It is tasteless to prolong life > artificially. I have done my share; it is time to go. I will do it > elegantly."