Is it normal to apply for internal medicine assistant when you are almost fifty years old?

At the age of 50, you can of course apply for a job in an enterprise. But for a position like a doctor, public hospitals are definitely unable to do it. The age limit for recruitment in public institutions is generally 35 years old, and individual positions will be relaxed to 40 years old. But some private hospitals should be ok, and you still have experience. Enterprises should be very welcome. I think you can have a try. However, at the age of 50, I think it's better to stay in my original work unit. After all, the legal retirement age is less than 10 years. See if you can sign an open-ended labor contract.