In the U.S., the medical cartel deliberately restricts the number of people who can become doctors in order to justify high salaries. They do this by restricting the number of students who can attend medical schools in the U.S., and by introducing a sort of hazing to reduce the number of people who want to become doctors. Some Americans avoid this by going to medical schools established by American doctors overseas precisely to deal with this problem, but the medical cartel takes other measures to make life difficult for these doctors. For instance, doctors educated in the United States are paid a modest salary during their residency, while American doctors educated to the same standards overseas are required to PAY a similar amount annually during their residency.
Of course the population has grown even as the supply of doctors has remained about the same, so we see two competing interests: one side wants to provide more doctors and reduce costs, so we import doctors from countries that already have too few (and these doctors are far more likely to cheat our healthcare system than locally born doctors), and introduce programs to let nurses do more work traditionally done by doctors, while at the same time we restrict the number of doctors educated in the United States and make it difficult for foreigners or even American doctors educated elsewhere to practice in the United States. We insist that only doctors can prescribe medication, although there are many, many countries that don't require doctor approval and do very well with that. One side wants to restrict the number of doctors to increase salaries, but as a side effect overworks doctors, while the other side insists on cutting costs and in doing so often increases them. The system is a complete mess, but it is very profitable - at the expense of the public. This monopoly can only exist because of government enforcement.