Medical Doctor (general practitioner)

Russian also has the word лекарь (an old-fashioned word for 'doctor'...now врач is the more common one) and лекарство (the everyday word for 'medicine') so I checked the etymology on Wiktionary (since Russian is one the few languages on that site that actually includes good etymologies). It traces the word definitively back to the Gothic language and Old High German of the Middle Ages while rejecting attempts of some linguists to trace the word further back to Latin and Greek roots.

As for how it ended up in so many languages, I'd simply observe the Goths got around, invading most corners of Europe at one time or another.

thanks #1. I was thinking it might have been the vikings from Sweden spreading the word (they founded Kiev and Rus after all), but Goths sounds like a better theory

In Polish the word "lekarz" means Medical Doctor, "lekarstwo" means medicine or cure, so it is quite similar to Russian. If I am not mistaken, in Slovak and Czech "lekaren" means pharmacy.

The Online Etymological Dictionary says (s.v. Leech sense 2):

obsolete for "physician," from Old English læce, probably from Old Danish læke, from Proto-Germanic lekjaz "enchanter, one who speaks magic words; healer, physician" (cf. Old Frisian letza, Old Saxon laki, Old Norse læknir, Old High German lahhi, Gothic lekeis "physician"), literally "one who counsels," perhaps connected with a root found in Celtic (cf. Irish liaig "charmer, exorcist, physician") and Slavic (cf. Serbo-Croatian lijekar, Polish lekarz), from PIE lep-agi "conjurer," from root *leg- "to collect," with derivatives meaning "to speak" (see lecture (n.)).

For sense development, cf. Old Church Slavonic baliji "doctor," originally "conjurer," related to Serbo-Croatian bajati "enchant, conjure;" Old Church Slavonic vrači, Russian vrač "doctor," related to Serbo-Croatian vrač "sorcerer, fortune-teller." The form merged with leech (n.1) in Middle English, apparently by folk etymology. In 17c., leech usually was applied only to veterinary practitioners. The fourth finger of the hand, in Old English, was læcfinger, translating Latin digitus medicus, Greek daktylus iatrikos, supposedly because a vein from that finger stretches straight to the heart.

Vinny, that's fascinating.

I assumed, not having done any research, that "leech" meaning a physician was connected with the use of leeches, the worms, in medicine. Or perhaps... runs to dictionary... the worm leech comes from the physician leech? H'm, my Chambers dictionary, which is not hot on etymology - in fact it's useless - seems to imply that "leechcraft: the art of medicine" comes from leech, the worm.

http://link.springer.com/content/pdf/10.1007/s002680010141.pdf#page-1
Two separate words.

russian also has lechit'sya - to get better/healed
does german have any sort of word from the same root?

If there is a modern German word from the same root, I will see what Kluge has to say about it.

One of the old names for what many now call the "ring finger" (fourth finger), was "leech finger" or "leech man." It's not absolutely certain why. One suggestion is that there was a belief that the finger had a vein that went directly to the heart, so there was more "healing power" in that finger. Or that the finger was a good one for bloodletting because of that vein. Or that doctors used the finger to administer salves. Or used to palpate skin. Or something.

(That non-existent vein to the heart is why wedding rings or other rings with emotional significance are worn on that finger.)

Discussed in the second paragraph of the Online Etymological Dictionary entry, Nutrax.