Internal medicine or general internal medicine is the medical specialty dealing with the prevention, diagnosis, and treatment of internal diseases. Physicians specializing in internal medicine are called internists or physicians in Commonwealth nations. Internists are skilled in the management of patients who have undifferentiated or multi-system disease processes. Internists care for hospitalized and ambulatory patients and may play a major role in teaching and research. Internal medicine and family medicine are often confused as equivalent in the Commonwealth nations. Because internal medicine patients are often seriously ill or require complex investigations, internists do much of their work in hospitals. Internists often have subspecialty interests in diseases affecting particular organs or organ systems.

Getting a regular eye exam may play a role in identifying the signs of some systemic diseases. "The eye is composed of many different types of tissue. This unique feature makes the eye susceptible to a wide variety of diseases as well as provides insights into many body systems. Almost any part of the eye can give important clues to the diagnosis of systemic diseases. Signs of a systemic disease may be evident on the outer surface of the eye, middle of the eye and at the back of the eye

Clinical pharmacy is the branch of pharmacy in which clinical pharmacists provide direct patient care that optimizes the use of medication and promotes health, wellness, and disease prevention. Clinical pharmacists care for patients in all health care settings but the clinical pharmacy movement initially began inside hospitals and clinics. Clinical pharmacists often work in collaboration with physicians, physician assistants, nurse practitioners, and other healthcare professionals. Clinical pharmacists can enter into a formal collaborative practice agreement with another healthcare provider, generally one or more physicians, that allow pharmacists to prescribe medications and order laboratory tests.

Initial psychiatric assessment of a person typically begins with a case history and mental status examination. Physical examinations and psychological tests may be conducted. On occasion, neuroimaging or other neurophysiological techniques are used. Mental disorders are often diagnosed in accordance with clinical concepts listed in diagnostic manuals such as the International Classification of Diseases, edited and used by the World Health Organization and the widely used Diagnostic and Statistical Manual of Mental Disorders (DSM), published by the American Psychiatric Association .