From whom did some medieval doctors learn treatments?
romans
arabs
greeks
normans

Medieval doctors learned how to treat patients from records of Greek medical procedures.  This was made possible through the documents of the Hippocratic Corpus where they applied the principles and procedures of examining the patient to applying different remedies. Other sources doctors learned to treat patients can found in pagan practices that involves supernatural elements but also the use of herbs to treat ailments.  Even monasteries cultivated the use of herbs as well followed the procedures in the Hippocratic Corpus.