A user interface 10, configured to be installed in a computing apparatus, for medical diagnosis, includes a display arrangement for displaying an image 28 of a part of a patient's body on a display device of the apparatus, the image 28 including an abnormality associated with that part of the patient's body. A library of representations 52-58 is accessible by a user, the representations 52-58 depicting abnormalities associated with that part of the body, at least some of the representations 52-58 being able to be displayed on the display arrangement. A selection means is operable by the user for selecting one of the representations and for overlying the selected representation 52-58 on the image 28 to enable the user to identify the abnormality.