By the turn of the nineteenth century medicine had become so complicated that there
started to emerge physicians who were medical doctors and those who were surgical
doctors. Further divisions rapidly ensued.
In the twentieth century, and particularly by the completion of the two great World
Wars, medical physicians had expanded to include general practitioners, pediatricians,
internists, psychiatrists, neurologists, cardiologists, respirologist, rheumatologists,
endocrinologists, nephrologists, gerontologists, gastroenterologists, etc, etc.