The disease descriptions in the vanilla game weren't that descriptive - they only gave you the mechanical effects of the disease and not what the disease actually is, nor its symptoms.
A earlier mod on the Nexus known as Disease Descriptions (made by Funsize_360) attempted to recertify that problem, but it felt like to me it was taking one problem and replacing it with another - in this case, the descriptions of the mechanical effects.
So, I decided to start my own version. Without blackjack and hookers, because that won't make sense.
What this mods does is add descriptions to the diseases in the vanilla game and the official DLCs, when available, and when I can get my hands on them. These descriptions retain information about the mechanical effects of the diseases, but also have a fluff description. This is really beneficial if you want to be really immersed into the game (or you are LPing it), as you would know how to react to whatever diseases you get.
Comes with both a Bash and a NMM installer, so users of either mod manager (or Mod Organizer) would have a simple installation procedure. Includes compatibility with Realistic Needs and Diseases, and any official DLC I can get my hands on that introduces diseases.