Elvin Medicine is very different from human medical practices. Elves tend not to use procedures like needles or surgery but rely instead on various elixirs to cure illness and injury.
The physicians mentioned in the books include Elwin Heslege, introduced in Keeper of the Lost Cities, and Livvy Sonden (aka Physic), introduced in Neverseen. Magnate Leto's father was also in this field of study.
Elwin is a Flasher and uses different colored lights that he creates and special glasses to diagnose patients. Livvy must use special coloured candles since she is not a Flasher, but the effect is the same.
A common place to buy medicines is Slurps and Burps, owned by Kesler Dizznee (Dex Dizznee’s father). One unspecified type of medicine elves use is modeled off the smallpox vaccine humans made.