1. A display apparatus comprising: a camera configured to capture at least one image of a user; a storage configured to store information about stress areas on a body in accordance with corresponding postures of the user; and a processor configured to determine a posture of the user from the at least one image captured by the camera, determine a position of one or more stress areas on the body corresponding to the determined posture based on the stored information about the one or more stress areas on the body, and process a stress-related image, in which the determined one or more stress areas are marked on an image corresponding to a figure of the user; and a display configured to display the stress-related image, wherein the processor is further configured to, if it is determined that the user maintains in one posture over a predetermined time based on the at least one image captured by the camera, change a displaying status of the one or more stress areas in the stress-related image.