During his final years Platt suffered from a palsy of his legs which confined him to a wheelchair for a majority of the time. He retired from the Senate in 1909 and was stricken by what was diagnosed as an acute attack of Bright's disease on May 28, 1909, a case so severe that his doctor publicly predicted his patient's imminent demise. Platt recovered, however, convalescing until late in January 1910, when he was deemed well enough to return home to his Manhattan apartment.