In my quest to get to the top of every single career track, I ventured onto the Medical track this week.  There were some odd occurrences, which were probably just coincidence.  

For example, this is the first time I have been offered the chance to switch career tracks halfway through - and I got that offer repeatedly. 

At least four times, the game asked if I wanted to switch my Sim over to the other career (Science, if memory serves).

This is also the track which has the most straightforward and boring requirements, but the most extra fringe activities.  As far as the core requirements, you just need Logic.  Lots and lots of logic.  Just keep your mood up, and you're set from that point.  (Unlike other tracks where you have to make friends, or participate in performances.)

After level 4, you are sent home with medical journals.  Reading these is optional, but it helps you advance faster.  They can be read pretty quickly, within a few hours or so.

All this other stuff happens beyond the basics.  Some of it was hugely confusing to me.  I have the Ambitions expansion pack, and I see now that your Sim is supposed to leave the hospital to go participate in these external events.  

At the time, all I knew was that I kept getting offers to hold vaccination clinics and such - right when my Sim had to go to work.  It was frustrating and a little odd.  I think they need to clarify some of the dialog boxes or something, because I was baffled by these.  (And sad that I never got to hold a vaccination clinic at the graveyard, which is where it kept being set.)

You also encounter medical emergencies while out and about.  My Sim got collared by a guy in the park who started having some kind of terrible tummy ache.  She scanned him with two different devices, then handed him a gigantic pill the size of a potato.  (Also, in the in-game terms, the size of a watermelon.)

Past a certain point, your Sim will be on call.  You can virtually guarantee being paged into the hospital at the worst possible times.  Which if you have ever had a job when you were on call, is exactly true.  (I had a job where I was on call one week out of four.  Worst job I've ever had.)

As a result, you will want to be sure to keep your Sim well-fed and well-rested during these times.  Inevitably they get called in right before bedtime, and go red afterward.  Don't let your Sim push their bedtime back too far, or they can end up really suffering!  (Alternatively: let your Sim push their bedtime back too far, because they can end up really suffering.)

The pay rate for the Medical track is one of the best.  You start at $22/hour, but by the time you're at level 10 you earn a whopping $480/hour, and work only three days a week.  Aside from an assortment of cute work outfits (I love the scrubs and the white doctor coat), you also gain the ability to tell a pregnant Sim the gender of their baby.  (I really miss the surgery station from Sims 2!)