First of all don't mistake an Internist for an intern; interns are doctors in their first year of residency, internists are specialists that use their expertise to diagnose and treat adults with all types of illness and health issues. The term internist, or doctor of internal medicine, derives from the German term Innere Medizin, which was a discipline in late 1800's Germany where physicians would combine the science of the laboratory with the care of patients. Many American Doctors in the early 1900's studied in Germany and then brought their knowledge back with them, along with the term internal medicine. Internists are sometimes called the doctor's doctor because often they are called in by physicians to help with a puzzling diagnosis. Internists go through seven or more years of medical school and are expected to be able to help any patient no matter what ailment they arrive with. Many internists also sub-specialize spending up to three extra years in medical school gaining a broad and deep understanding of a certain specialty, such as cardiology. Internists take pride in caring for their patients for life and are well equipped for any medical situation.