General practitioners have been declining in numbers since around 1910. Requirements have been an MD and one year of residency followed by a licensing examination. Usually, general practitioners are older and have been in practice for many years. They make up for less postgraduate work by increased clinical experience. General practitioners treat the full spectrum of medical disorders and refer to specialists when needed.
Internists specialize in nonsurgical treatment of adults.
They take a three-year residency in advanced treatment and management of most common medical problems. Some internists will take further training in a subspecialty. Examples are, cardiology, oncology, rheumatology. When internists refer to a subspecialist for diagnosis, they usually maintain treatment supervision. What questions to ask.