I’m sure there are many great posts on the web and on here that give you advice on how to decide what to do when you grow up. I figured I should weigh in on the topic as well. First and foremost, you have to do some inner reflection and decide what you value. Do you prefer procedures? Do you enjoy patient-doctor relationships or are you relatively indifferent towards it? Do you like research and want to pursue that as part of your career? What kind of lifestyle do you want? Once you’ve decided on those basic ideas, you can start narrowing down fields. What you should be evaluating is how you envision yourself as an attending in those respective fields and how being in that environments affects you. These basic tenets will (usually) give you a decent idea of what you should go into.
Obviously, these ideas aren’t revolutionary, and I’m sure you’ve heard most, if not all, of them before. One thing I would recommend is to also consider the negatives of your potential career choice. A lot of times, we fixate on all of the positives and rarely give much thought to the negatives. Every field has drawbacks. I think figuring those out and deciding whether you would be happy and able to deal with those drawbacks is key. To me, this is analogous to the rate-determining step of chemical reactions (sorry just brought you back to college chem), where the OVERALL rate of the reaction is determined by the SLOWEST step–the rate determining step. To me, the negatives of the field are the rate-determining step. If you can get past them, you will run just fine!