When you say public speaking, is it just speaking in front of a crowd, or does it also include 1 on 1 interviews?

It if is just speaking in front of large crowds, you probably won't be bothered any more in med school than you were in college - med school didn't require me to do any public speaking as far as I remember.

The only time it may be a factor is if you have to give a presentation in front of your "team" during your 3rd and 4th year - the teams usually consist of your attending physician (the staff doctor for the med school), a few residents and interns, a few other medical students, and sometimes a few people from other disciplines. It is not really the same as public speaking as in giving a lecture, but more of a table discussion where you have to explain information about your patients to the rest of the team.

If this is something that REALLY bothers you, you may want to seek help from a psychiatrist or psychologist who is experienced in social phobia. There is also a support group around in many places, I believe called Toastmasters - that helps people get exposure to public speaking: Toastmasters

From what I know, I would think that exposure therapy, like what Toastmasters can offer, would be the best way to desensitize your anxiety about public speaking. The other option is to take a medication like Paxil which is FDA approved for social phobia (although I would guess that any of the SSRI's would be equally effective) - for some people it can be very effective, but you'll have to weigh the risks and benefits, especially looking at how often this is a problem for you.

Ridiculous disclaimer: this information is not meant to be construed as advice - it is merely information that I am providing in a public forum.