Boris Gudenuf
Deity
1. Could have a new District called something like 'City Services' which could include the Sewer/Water Supply (both Health Boosters), Hospital, possibly a Research Hospital as the highest Tier building in it. More than one District is, I think, Overkill.I'd like to get an opinion on how much is too much for some people:
Buildings/Districts: I don't think the concept could exist without some buildings, maybe a whole district, being geared towards this. Housing already has its own district and buildings, and if Health were to replace it, I don't see the problem.
Great People: I don't think we need a specialized group of Great people to deal with Health. That role could be given to various others. I can see at least one Great Scientist/ Great Prophet etc. having abilities geared towards it.
Civilian Units: I know a lot of people hate having many different civilian units, but Plague Doctors honestly would look cool.
Resources: I've already mentioned this, but having some resources that could have health would be fine. Maybe you could upgrade one of them by founding a corporation, considering I want those to also return.
World Congress: Obviously we would need a Pandemic emergency, right? Using your science to research a cure and being able to send aid to other civs seems like the most mini-game part. But of course, isn't every World congress emergency already like a mini-game?
2. Great Doctors for much of history were part of the Great Scientist group: Galen and Aristotle both wrote on many subjects including medical ones. There's no reason to sub-divide Great People. What might be added is a Boost to getting as the next Great Scientist with a medical/Health benefit if you are suffering from Health or Pandemic effects in your Civ.
3. IF a civilian unit of 'Plague Doctor' or something similar is added, they should have more than a single function related to events that you might be able to avoid completely: in addition to ameliorating Plague, possibly a civilian Doctor would be required in a city or settlement founded in Unhealthy Terrain to keep the settlement viable. Think the horrible death rates among European settlers in the Caribbean in the 16th - 17th centuries where they could really have used such help, or the American medical research that fought off Yellow Fever in Panama and made the building of the Panama Canal possible where it wasn't not that many years earlier without that help.
4. Resources might be the easiest thing to implement. As posted earlier, several Resources in the game already have Health benefits: Spices and Honey for two. Mercury famously for STD, although including that in the game is probably Problematic.
5. Among possible Technologies with potential Health benefits:
Medicine could be added in either the Classical or Ancient Eras. Formalized and written texts on herbal medicine were already available in both Egypt and China before 1500 BCE, the Ancient Era, and in rthe Classical Era we had the writings and medical discoveries of Hippocrates, Galen, Dioscorides, etc.
Charcoal, also a fuel for relatively high-temperature kilns making stoneware pottery and Iron smelting, was also used to purify water by both Classical Greeks and Phoenicians - a Health 'by-product', so to speak, for the early Classical Era.
Germ Theory, the discovery by Pasteur in the mid-Industrial Era, had massive health effects which translated into dramatically reduced Urban death rates and population increases. The Pasteur Institute would be a good Modern Wonder to combat disease, plague, and Health issues as well.
Pharmaceuticals, also late Industrial/Modern Era, based on discoveries like antiseptic chemicals, aspirin and derivative pain-killers, culminating in antibiotics like penicillin.