Is It Possible To Study Science/medicine/research And Pursue That As A Career, Even If You've Majored

is it possible to study science/medicine/research and pursue that as a career, even if you've majored in a humanity for undergrad and really have no prior work experience in the research field?

Yes and no. 

You can go to medical school with no research experience (I did) but you will have to have the basic science pre-med background. You can major in whatever you want, though. 

To pursue a scientific career you’re going to have to have some sort of STEM background and training, whether it’s technical school or bachelors/master’s level education. It’s hard to know what the requirements are without knowing more specifically what type of job you are thinking of.

Careers in scientific research are very competitive, actually. There is huge pressure to publish and there are fights for grant funds and university positions. You could work as a lab assistant in some cases with on-the-job training, but in most cases you’re going to need a pretty solid STEM background if you are going to design or run experiments. You have to have learned the basic lab techniques and the science behind your research to be able to actually do the research. 

In all these cases, even with a degree in the humanities, you can go back to school and bolster your science credentials, but going in with no experience is going to be tough.