I could not imagine leaving medicine to fly an aeroplane. Having said that I have known several who have done just that, however most of them still practice either as a part time thing or as CAA AME's. I still remember one particular chap who wandered round the crewroom wearing 4 bars on his shirt and a stethoscope around his neck as he did a quick class1 renewal before flying.
My dad was a doctor. He had a good career and now enjoys a pension far in excess of anything I will ever get. He still does the odd bit of consulting inbetween what seems to be permanent holidays. Once I reach 65 that's it. Can't afford to retire so Ill be doing whatever required (B + Q?) to keep body and soul together.
My "career" has featured redundancy (4 times) and always being at the wrong end of the list as a result. Very good chance as retiring as an FO. Watched all my peers gain command/training whilst being stuck on the sidelines. I enjoy the job and like the company I work for but if I had inherited my fathers brains rather than just his temper, I would have followed him into medicine.
Son has decided to follow another profession daughter will do likewise. I put no pressure on either but am very glad they will not be sucked into the aviation business. Apart from anything else, the price of oil over the next 15 years will probably see most airlines off. Missed the golden age but at least it will see me out. Would not want to be starting out now and feel very badly for anyone who is depending on this to pay the bills for the next 30-40 years.
Only one real bit of advice. Have a plan B. Chances are you will need it.