There are multiple sources for images available. These are just a few suggestions for where to find appropriate images for your presentation.
When using the library databases to search for your disease, the results page will include a section of "Related Images" on the right-hand side of the screen.
You could also use specific databases such as Nursing and Allied Health Source (Proquest) to search by source types such as pamphlets, blogs, websites, and videos(see the image in the box to titled Images); Gale Interactive: Human Anatomy which allows users to manipulate 3D models of the body; Health Source: Nursing/Academic Edition will search articles for charts, diagrams, graphs, and photographs; and Nursing Reference Center gives access to patient education resources as well as continuing education modules which often include usable images.