1. An information exchanging method comprising: acquiring increments of medical images of a same region of a first object relative to a reference image; determining a first change trend of the medical images according to the increments; sending first information to a terminal of the first object when the first change trend exceeds a preset threshold, wherein the first information indicates the first change trend; and sending appointment information of a medical institution to the terminal, wherein the appointment information indicates an available medical resource of the medical institution.