How many diseases out there don't have a name? And what happens to these people?

Evolving. There is always some new strain of virus or bacteria evolving, and several groups of shared symptoms (syndromes) that occur based on changes in the environment and genetics. They show up in clinics and hospitals from time to time, and are addressed by the collective healthcare system. If you're curious, come on -- get in the game -- join the team and contribute to wellness in any way you can!