Medical Dictionary for Pages

I love using Pages but as a medical student, typing up notes etc. is very annoying to see red lines everywhere. I know the terms are spelled correctly but Pages wants to mark it as wrong. Is very distracting even when there's red all over the page. In Microsoft Office, I have the ability to import a custom medical .dic file and it works well. I don't want to use Microsoft Office however because I like some of the features of Pages. However, this one issue may prevent that. Its entirely to frustrating and distracting to see so much red in a document when I know terms are spelled correctly. Any help?