A medical diagnosis apparatus obtains a signal for generating an image of an observation target and causes an external display device to display an observation image based on the obtained signal to perform diagnosis. The medical diagnosis apparatus includes: a detection unit configured to detect a shape and spatial position of a finger of a practitioner； an executable command selection unit configured to select one or more commands executable by the medical diagnosis apparatus in accordance with the shape and the spatial position of the finger of the practitioner； a command image generation unit configured to generate a command image corresponding to the one or more commands and to generate a finger shape image indicating the shape of the finger of the practitioner； and a display image generation unit configured to generate a display image using the command image, the finger shape image, and the observation image.
