'Internal medicine' is a very broad term to describe a large range of medical careers, including physicians, surgeons, anesthesiologists, and others. This broad range of careers does have a range of common elements in the form of the application and medical treatments inside the body, which is where the term is derived.
These types of medicine involve intensive practical training over and above the core elements of medical degrees. Each of these careers is a type of specialization requiring extensive knowledge, skills and involves acquisition of practical experience under supervision prior to commencing practice.
Each of these careers may include hospital, clinical and private practice. Internal medicine careers are very much dictated by qualifications, areas of specialization and tangential career moves dictated by both personal preference and employment opportunities.
Career advancement may involve crossing streams of employment, for example moving from hospital practice to private or clinical practice. Each has additional career options in the area of teaching, academic studies and research.
Career success in internal medicine isn't easily defined. Because of the range of career options and the potential for development of private practice, success can be measured as a range of achievements within the fields. The common element in internal medicine is that these careers are ideal for truly talented people having exceptional skills and able to deal with personal responsibility.
A career as a surgeon, for example, may include incredibly demanding professional situations requiring exceptional skills. If you are interested in medicine, and looking for a challenge to your skills and knowledge, internal medicine is perhaps the first option you should evaluate.