How is Tsunade going to die ?

[Natsu Shazneel]

She will die by the hands of a reincarnated Madara. Who will than use her cells to revive himself.

 

[senjusana]

She will die due to old age. Dat Senju and Uzumaki genes.

 

[Conspirator.]

One day, someone will slip too much salt into her dinner and she'll die gracefully like the slug she is.

 

[Everztar]

of old age. remember that she looks 20 but is 65-70 by gaiden
she was 55 in shippuuden

 

[FemmeFatale]

Trick question an immortal can't die.