I have a character who is involved in the typical, secretive supernatural shenanigans of my setting (think something like a superhero, a monster hunter, or the vampires in Vampire: The Masquerade) but has a day job as a medical doctor in a Western country. Being a doctor is their main job, as their supernatural work is mandatory (they have no choice in the matter) but doesn't pay anything. The supernatural is also not medical-themed in this setting so it is not like they are doing medicine by day and fighting plague demons by night that might lend them to a particular area of medical specialization.
The problem with being a medical doctor is you often have long hours and you don't get to choose when you get to work. Sometimes you have to work ER or operating room shifts and if you live in a small town and are the only doctor you will get called in every time there is an emergency, even if you are a general practitioner. And before that being a med student often demands long hours and work in very difficult positions.
At the same time, you can't ignore the plot when it comes calling if you are a superhero, monster hunter, etc. People will die if you're a doctor and don't operate on them, but they will also die if you ignore the supernatural nonsense that is killing and eating people. While that conflict makes for good tension in small doses if it happens often enough you have to wonder how the character keeps their job, especially since doctors can get in big trouble if they don't fulfill their duties enough times.
On the other hand, the character wants and prefers to be a doctor, despite being drafted into dealing with the supernatural (which they don't like), so the character is unlikely to say "well, my life situation prevents me from having a career in medicine".
This is a common trope for people living a double life in supernatural fiction (e.g., Spider-Man and Daredevil have this as chronic issues), but I've never seen it done with medicine.
I'm trying to figure out what branch of medicine would be the best one for this person to be in, given they already have the commitment of dealing with supernatural issues before they even enter medical school. I.e., what branch of medicine/medical career would be the most amenable for someone hiding a supernatural secret and occasionally having to take unexplained absences?
I'm asking this here because there isn't really a good real-world analogue for "doctor has to moonlight by fighting evil". About the closest I've been able to find is when doctors have chronic health issues, but having talked to IRL doctors usually what they do in these cases is power through the health issues and do the job anyway. For most doctors I've talked to practicing medicine is often the first and primary concern. This is a case where issues come up that the character simply cannot back-burner for the sake of their job.