The diagnostic process involves 5 steps: 1) taking a patient's history, 2) examination, 3) provisional diagnosis, 4) investigations, and 5) final diagnosis. The examination includes general, extra-oral, and intra-oral assessments of things like appearance, mental state, teeth, oral mucosa, lymph nodes, jaw, physique, and vital signs. Examining a swelling involves inspection of characteristics like site, size, and borders, followed by palpation of tenderness, temperature, consistency, and mobility.