Scope of Medicine

Unlike doctors who specialize in conditions affecting one organ, for example, cardiologists (heart), nephrologists (kidneys), or dermatologists (skin), internists are trained to treat diseases which can affect several organs simultaneously or successively, for example, immune disorders such as lupus erythematosis, Wegener’s disease, Scleroderma, that can affect the nervous system, the skin, the kidneys, the lungs and other organs. Many of these diseases are difficult to recognize and rare enough to pose complicated diagnostic issues to those without the necessary training and experience. Internists also usually have expertise in treating infectious diseases such as HIV infection, tuberculosis or parasitical infections. Often they have a sub-speciality: either Pulmonology, cardiology, nephrology, haematology, etc. They also bring to patients an understanding of preventive medicine, men’s and women’s, substance abuse, mental health, as well as, effective treatment of common problems of the eyes, ears, nervous system and reproductive organs.

Principles of Diagnosis

The main tools that a doctor has to work with are the medical history and a physical examination of the patient, but this holds particularly true for internal medicine. The internist takes note of subtle description of the disease (for example, cyclic shallow and deep breathing, as in Cheyne-Stoke’s respiration, or persistently deep breathing, as in Kussmaul’s) or physical signs (for example, “clubbing” in many pulmonary diseases), all are important tools in guiding the diagnostic process. In medical history, the “Review of System” serves to notice symptoms of the disease which a patient may not normally have mentioned, and the physical examination typically follows a structured fashion.

With the information to hand, the internist is generally able to generate a “differential diagnosis”, or a list of possible diagnoses that can explain the constellation of signs and symptoms.

In order to narrow down the differential diagnosis, blood tests and medical imaging are used. These can also serve screening processes, for example, to identify anaemia in patients with unrelated complaints. Commonly performed screening tests, especially in older patients, are X-ray of the chest, a full blood count, basic electrolytes, renal function and blood urea nitrogen.

At this stage, the internist will often have already arrived at a diagnosis, or a list of possible diagnoses. Specific tests for the presumed disease are often required, such as a biopsy for cancer, microbiological culture etc.

Treatment

Internal Medicine is mainly focused on the art of diagnosis and treatment with medication, which can be antibiotics, steroids, or other types of drugs. Sometimes a surgical treatment is also required and the internist works then with the relevant surgeon (general surgery, Orthopaedics, thoracic surgery, vascular surgery, etc.)