Health care has come up a number of times in the last few weeks of daf yomi Talmudic readings. For instance, at Shab 123a the sages discuss the needle used to remove splinters, the use of emetics, and the (proto-chiropractic?) readjustment of the dislocated limbs of a newborn. There is also a fascinating conversation about about the measures that may be taken, regardless of Sabbath prohibition, to take care of a women before, during and well after labor, e.g. lighting a lamp for a blind woman (128b-129a). (Plus, the halakhah that the umbilical may be not only tied but also cut on shabbat.) Here Mereimar teaches the principle that rabbinic laws "are interpreted leniently for an uncertainty involving life" (safeq nefashot le-heqel).
Having read so much about folk medicines in tractate Shabbat, I looked at Jewish Magic and Superstition by Joshua Trachtenberg (1939!), still a fount of information and highly readable. In the long chapter on medicine, he digests supernatural etiologies of disease, bloodletting, psychic treatments, homeopathy, charms, incantations, magic names, use of Torah verses and scrolls, gross potions, misc. healing devices, name change, and herbs. this passage caught my eye:
[Medieval] Northern Europe, walled off from the enlightenment that radiated from the Arab lands, produced not a single Jewish physician of note. Jewish practitioners of medicine there were aplenty, but their science was little more than a faint reflection of the learning of their southern co-religionists. … It is unfair to suggest… that Jewish medical superstition is to be regarded mainly as an imitation of the Christian. … the rationale of superstition and magic in medicine was part and parcel of the Jewish cultural heritage.” (194)
It's hard for some of us to admit the degree of medical and other superstition within Judaism, but that's one kind of knowledge they had available. And it's nice to remember the level of Ashkenaz during the golden age of Sefarad...