You can use downtime between adventures to recover from a debilitating injury, disease, or poison.
After three days of downtime spent recuperating, you can make a DC 15 Constitution saving throw. On a successful save, you can choose one of the following results:
- End one effect on you that prevents you from regaining hit points.
- For the next 24 hours, gain advantage on saving throws against one disease or poison currently affecting you.
Suppose character Alpha is afflicted with Sewer Plague, the bite of a diseased Giant Rat, or some other disease, injury, or long-acting poison on an adventure, and another party member Delta has proficiency with Medicine. No potions or spells are available to either of them. Alpha's choices are to use downtime to Recuperate, or ask Delta to use their Medicine proficiency to help Alpha recover.
Intuitively it seems like Medicine should help, but the mechanics for using Medicine to treat a patient are (perhaps deliberately, I know) fuzzy. Under strict RAW Delta can diagnose Alpha but there's no clear generic method for treating a "patient" using Medicine proficiency, though a character can Recuperate unassisted as described. I didn't find anything in Sage Advice. Are there any other rules that are relevant or references that might help a DM rule for their table?