Lawyers use all sorts of non-legal research resources, including medical ones.
As is the case with any specialized subject research, you need to develop a research strategy to make sure you begin at the beginning, use the right search terms, identify relevant journals and indexes and catalogs, and have a system for recording your progress so you don’t miss anything or duplicate your research.
And, as is the case for any specialized research (e.g. business, law, music, etc.), it helps to consult a specialist – a medical librarian or research specialist in this case.