Internal Medicine is the medical specialty that addresses illness of the adult in the same way a pediatrician is a specialist for the very young, or a geriatrician for the very old. So as Internists, we cover the age range of approximately 16- 75 years of age, although these are not very hard boundaries.

Internists are trained to manage particularly complex or multisystem conditions that single-organ-disease specialists may not be comfortable to deal with. They may be asked to tackle undifferentiated presentations that cannot be easily assigned to a single organ, such as dyspnea, fatigue, weight loss, chest pain, confusion or change in consciousness state. Internists manage serious acute illnesses that affect multiple organ systems at the same time in a single patient, and they may manage multiple chronic diseases or “comorbidities” that a single patient may have.

Internists do not provide less expertise than single-organ specialists, rather, they are trained for the specific role of caring for patients with multiple simultaneous problems or complex comorbidities.

So, if you have symptoms of ill health but are not sure what caused the symptoms, or have consulted a single organ specialist to no avail, seeking advice from an specialist for Internal Medicine is likely the best choice you can make.

If comparing Internal Medicine with General Practitioners and medical subspecialties such as cardiologists, gastroenterologists or respiratory physicians, then diving may serve as an explanatory metaphor.

Like a snorkeler who may swim close to the surface, but easily enter small pools, a General Practitioner would assess and treat for common illnesses in the adult such as “common cold”,“indigestion”, but also “diabetes” including “leg wounds”, and venture into dealing with such issues also in pediatric patients or do simple gynecology test such as PAP smears and the like.

While doing this, the General Practitioner may become aware of more complex issues that are outside their reach- just like the snorkeler might see an interesting shape deep in the water and wonder if this is a shipwreck, or a reef or something quite different.

The Internist would then be more like a scuba diver, with a license to go much deeper. Focusing on adult patients, an Internist can do in-depth assessments to establish a proper differential diagnosis. In a patient with, say, chest pain, the pain can originate from the heart, the lungs, the stomach, the spine, the breastbone, the ribs- each with a different treatment, some of them even mutually exclusive. To stay in our diving metaphor, the Internist would be like the scuba diver who can go deep enough not only to see that, indeed, there is a shipwreck, but would know to read the ships name and how it came to be in that place.

If such a scuba diver, however, were to find a safe inside the wreck and wanted to know if there is anything of value inside, they would need to get support from divers with even more hardware. In medicine, this would be the role of the sub- specialists, such as cardiologists or gastroenterologists. If the internist has found out that their patient’s chest pain is due to an illness of the heart, a cardiologist might be called upon to do a coronary angiogram to visualize the location of a coronary blockage and advise if it can be removed my medication alone, with the help of a balloon and stenting procedure, or would require bypass surgery.

Thus, an internist can help adult patients establish a diagnosis or cause of their symptoms, can often treat them but sometimes needs the help of more a narrowly specialized colleague for the very last step of the way.