medical practice diagnosis

A physician's job is to know the human body and its functions in terms of normality (homeostasis). The four cornerstones of diagnostic medicine, each essential for understanding homeostasis, are: anatomy (the structure of the human body), physiology (how the body works), pathology (what can go wrong with the anatomy and physiology) and psychology (thought and behavior). Once the physician knows what is normal and can measure the patient's current condition against those norms, she or he can then determine the patient's particular departure from homeostasis and the degree of departure. This is called the diagnosis. Once a diagnosis has been reached, the provider is able to propose a management plan, which will include treatment as well as plans for follow-up. From this point on, in addition to treating the patient's condition, the provider educates the patient about the causes, progression, outcomes, and possible treatments of his ailments, as well as providing advice for maintaining health.
It should be noted, however, that medical diagnosis in psychology or psychiatry is problematic. There are differing theoretical views toward mental conditions and few objective tests available for various major disorders (e.g., clinical depression), so a causal analysis with respect to symptomatology and disorder/disease is not always possible. As a result, most if not all mental conditions function as both symptoms and disorders. There are often functional descriptions provided for psychological disorders and these are vulnerable to circular reasoning due to the etiological fuzziness inherent of these diagnostic categories. (BDG, 2006)