What is Internal Medicine?

Internal Medicine is a branch of medicine that focuses on the diagnosis, treatment, and prevention of diseases affecting internal organs and systems in the adult human body. Internal medicine is a broad field that covers a range of subspecialties, including cardiology, endocrinology, gastroenterology, hematology, infectious diseases, oncology, pulmonology, and rheumatology. With a strong emphasis on evidence-based medicine and patient-centered care, internal medicine plays a critical role in improving the health and well-being of individuals and communities. (1)

Overview and Definition

Internal medicine, also known as general internal medicine, is a medical specialty focused on the prevention, diagnosis, and treatment of diseases that affect the internal organs and systems of the adult human body. Physicians who specialize in internal medicine are called internists and are highly skilled in managing patients with undifferentiated or multi-system diseases. They provide care for patients who are hospitalized or who are receiving outpatient care and also contribute significantly to teaching and research. 

Internists have completed postgraduate training in internal medicine and are not to be confused with interns, who are doctors in their first year of residency training. Due to the serious nature of the illnesses they treat and the complexity of investigations required, internists often work in hospitals. They may have specific subspecialty interests in diseases affecting particular organs or systems, and the certification process and available subspecialties may vary depending on location. (2)

Education and Training 

The education and training of internal medicine specialists typically involve a rigorous and lengthy process that varies depending on the country and region. In most cases, individuals interested in becoming an internist must first complete a four or five-year undergraduate degree in pre-medical education, which covers the basic sciences, including biology, chemistry, and physics.

After completing undergraduate studies, individuals must gain admission to a medical school, which typically takes another four years to complete. Medical education programs can vary in length and structure depending on the country, but in the United States, for example, the medical school consists of classroom-based instruction, clinical rotations, and patient care experiences.

After graduation, new medical graduates must complete a period of supervised practice, which can be referred to as an internship, foundation program, or conditional registration period. This period typically lasts one or two years and is designed to provide new physicians with the opportunity to apply their skills in a supervised setting and gain practical experience.

Once the supervised practice period is completed, individuals may choose to pursue specialty training in internal medicine. This typically involves a highly competitive residency program that can last for three years, with a focus on secondary and tertiary care. In many countries, individuals who complete their residency may choose to pursue further subspecialty training, called a fellowship, which can take an additional two to three years.

Throughout their training, internal medicine specialists must also pass rigorous licensing and certification exams to ensure that they meet the standards of their respective medical boards. This extensive education and training process helps to ensure that internists are well-prepared to diagnose, treat, and manage complex medical conditions and provide high-quality care to their patients. (3,4)

Practicing as an Internist

Internal medicine physicians possess a vast knowledge of the human body and its interconnected systems, making them highly skilled and adaptable professionals. They play a critical role in diagnosing and treating a range of illnesses and medical conditions in adult patients, including chronic diseases such as diabetes, hypertension, and heart disease. In addition to providing compassionate care, internists are trained in health promotion and disease prevention.

To become an internal medicine physician, one must complete medical school and a three-year residency program in internal medicine. Subspecialty training is also available for those who wish to specialize further in areas such as cardiology or infectious diseases. Internal medicine physicians work in a variety of settings, including outpatient clinics, hospitals, and as hospitalists who care exclusively for patients in the hospital.

Their expertise in complex medical issues, critical thinking skills, and ability to thrive in challenging and dynamic environments make them highly valued by both patients and other medical professionals. It is important to note that internal medicine physicians should not be confused with interns, who are doctors in their first year of residency training. (5,6,7)

Procedures Performed

Internal medicine specialists are responsible for conducting or prescribing medical tests, procedures, and surgeries that are appropriate for their patient's medical conditions, overall health, and personal wellness goals. These procedures can vary significantly depending on the patient's diagnosis and treatment plan and are often performed by experienced and skilled healthcare providers such as internists, nurses, and other specialists.

In some cases, additional training and medical qualifications may be required to ensure that these procedures are performed safely and effectively, with minimal discomfort to the patient and optimal results. The procedures performed in internal medicine include:

• Flexible sigmoidoscopy
• Arterial puncture to analyze blood gasses
• Endotracheal intubation
• Nasogastric (NG) tube placement
• Venipuncture (“blood draw”) to test blood
• Urinary catheters placement
• Intravenous (IV) line insertion

Certain internal medicine specialists have received training in performing intricate and potentially invasive diagnostic and treatment procedures, such as lumbar punctures, thoracenteses, and paracentesis.

Examples of other categories and types of tests and procedures that internists may administer or carry out include:

• Gastroenterology: includes upper and lower endoscopy, endoscopic retrograde cholangiopancreatography (ERCP), esophageal manometry, stent insertion, liver biopsy, endoscopic ultrasound
• Allergy: includes skin testing, rhinoscopy
• Endocrinology: includes dynamic hormone testing, bone density testing, and thyroid biopsy
• Hematology/oncology: includes bone marrow biopsy, lymph node biopsy, stem cell transplant, and plasmapheresis
• Cardiology: includes echocardiograms, coronary catheterization, cardiac stress testing, angioplasty, cardioversion, stent insertion, pacemakers, electrophysiology testing and ablation, implantable defibrillators, placement of intra-aortic and intra-ventricular devices
• Rheumatology: includes joint aspiration and therapeutic injection
• Pulmonary: includes intubation and ventilator management, chest tube thoracostomy, bronchoscopy, tracheostomy placement
• Renal: includes kidney biopsy, dialysis

Ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI) are imaging technologies commonly employed by internal medicine and various other medical specialties to aid in the performance of invasive procedures. These procedures may involve the use of flexible, fiberoptic instruments to access difficult-to-reach areas of the body. (8)