A device for obtaining disease information of a user, the disease information relating to diseases that include facial symptoms, the device comprising: an imaging unit; a display; a storage configured to store facial symptom information of at least one disease associated with facial condition information; and a controller configured to: monitor a server to which a user is connected to receive from the server a plurality of first images including a face of a user and facial condition information of the face extracted from the plurality of first images; control the imaging unit to capture or receive a second image including the face of the user and to extract second facial condition information of the face from the second image; determine, as a reference image to be compared with the second image, a first image, from among the plurality of first images, corresponding to a range of values of a characteristic within which a value of the characteristic of the second image falls, wherein the characteristic corresponds to a photographing circumstance at a time of capture of the second image, the photographing circumstance comprising at least one of a brightness of lighting, a direction of the lighting, and a color temperature of the lighting; and compare the second facial condition information and first facial condition information extracted from the determined first image, and extract a difference in the first facial condition information and second facial condition information; obtain disease information of the user by comparing the extracted difference with the stored symptom information corresponding to the facial condition information; and control the display to output the second image and the disease information of the user corresponding to the facial condition information, wherein the controller is configured to monitor the server for a newly-added first image including the face of the user, by periodic communication with the server. an imaging unit; a display; a storage configured to store facial symptom information of at least one disease associated with facial condition information; and a controller configured to: monitor a server to which a user is connected to receive from the server a plurality of first images including a face of a user and facial condition information of the face extracted from the plurality of first images; control the imaging unit to capture or receive a second image including the face of the user and to extract second facial condition information of the face from the second image; determine, as a reference image to be compared with the second image, a first image, from among the plurality of first images, corresponding to a range of values of a characteristic within which a value of the characteristic of the second image falls, wherein the characteristic corresponds to a photographing circumstance at a time of capture of the second image, the photographing circumstance comprising at least one of a brightness of lighting, a direction of the lighting, and a color temperature of the lighting; and compare the second facial condition information and first facial condition information extracted from the determined first image, and extract a difference in the first facial condition information and second facial condition information; obtain disease information of the user by comparing the extracted difference with the stored symptom information corresponding to the facial condition information; and control the display to output the second image and the disease information of the user corresponding to the facial condition information, wherein the controller is configured to monitor the server for a newly-added first image including the face of the user, by periodic communication with the server. monitor a server to which a user is connected to receive from the server a plurality of first images including a face of a user and facial condition information of the face extracted from the plurality of first images; control the imaging unit to capture or receive a second image including the face of the user and to extract second facial condition information of the face from the second image; determine, as a reference image to be compared with the second image, a first image, from among the plurality of first images, corresponding to a range of values of a characteristic within which a value of the characteristic of the second image falls, wherein the characteristic corresponds to a photographing circumstance at a time of capture of the second image, the photographing circumstance comprising at least one of a brightness of lighting, a direction of the lighting, and a color temperature of the lighting; and compare the second facial condition information and first facial condition information extracted from the determined first image, and extract a difference in the first facial condition information and second facial condition information; obtain disease information of the user by comparing the extracted difference with the stored symptom information corresponding to the facial condition information; and control the display to output the second image and the disease information of the user corresponding to the facial condition information, wherein the controller is configured to monitor the server for a newly-added first image including the face of the user, by periodic communication with the server.