As for the difference between primary care and internal medicine the short answer is that not internal medicine is a type of primary care. Internal medicine differs from other main forms of primary care in its demographic specialization.   For instance, there are many similarities between internists and family practitioners. Neither physician specializes in one type of illness, but both treat a wide variety of illnesses. The main difference between internists and family practitioners is that internists only treat adults, while family practitioners treat the entire family.   The practice of family medicine, for example, allows physicians to provide comprehensive care to the entire family. In addition to providing preventive care, a family physician also manages a variety of medical problems.   Internal medicine physicians, however, can provide a wider range of primary care, including but not limited to diabetes, high cholesterol, and high blood pressure. Moreover, internal medicine doctors specialize in diagnosing and treating complicated medical cases, especially those involving uncontrolled or multiple health issues that make it difficult for a diagnosis to be made.