Medical diagnosis

Anatomy or system affected: All

Definition: A methodical evaluation of symptoms and complaints through interview, observation, testing instruments, or procedures, including biological tests, to determine if an illness is present.

Indications and Procedures

When individuals see healthcare professionals for treatment, they are evaluated to determine the nature of their concerns. The process of evaluation usually involves a combination of assessment, screening, reassessment, and then formal diagnosis. Patients typically initially describe their experience, concerns, and history, and then the professional asks more questions and may follow up with screening questions.

Screening questions identify risk for any more serious conditions, for which additional assessment may be needed. Screening is inexpensive and involves spending a small amount of time on questions that are easy to ask and answer, providing a determination of whether the person is at risk for a specific problem. If the screening result is positive, then the risk is present and further evaluation is needed; if it is negative, then the risk is deemed absent and no further evaluation is needed. Unfortunately, no screening process is perfect, so sometimes, there are false negatives. This is why it is important that if problems continue, individuals seeking care get second opinions or return for evaluation.

If a screening result is positive, then additional assessment is conducted to determine if a diagnosable condition is present. This usually involves a complete symptom history, comparing the symptoms described to known disorders, and doing differential diagnosis. If the information collected does not yield anything, then the screening process resulted in a false positive. If, on the other hand, the collection of information yields enough information to show that the criteria for a condition are satisfied, then a diagnosis is confirmed.

An example of how diagnosis may work is as follows. A person comes to an emergency room, has alcohol on the breath and no other medical problems, and is screened positive for alcohol problems by a nurse asking a few questions. Additional assessment is done by a psychologist, and they determine that the individual meets the criteria for alcohol dependence. Alcohol dependence is a condition with seven criteria, and an individual who demonstrates three or more in any twelve-month period qualifies for the diagnosis. The patient might report having tolerance (needing to use more to get the same effect), withdrawal (adverse physical symptoms caused by stopping use), and a persistent desire to quit, all in the past year. The psychologist then diagnoses the patient with alcohol dependence, and treatment will address that problem.

Uses and Complications

Diagnoses are useful in facilitating effective and quick communications among treatment professionals and other stakeholders in the care of the client. These stakeholders include other treatment providers, insurance companies, researchers in epidemiology and other areas of science, and the clients and their families.

One complication related to diagnoses is that many diagnoses have symptoms that overlap, and methods of differential diagnosis are always being developed. As such, it is possible for misdiagnoses to occur. When this happens, individuals may be treated for the wrong problem, or even overdiagnosed or underdiagnosed, and thus not properly treated. As such, when dealing with more serious conditions that are costly or potentially dangerous to the patient to treat, it is often advised to use multiple methods of diagnosis and even seek secondary opinions to confirm the diagnosis.

Perspective and Prospects

Since the beginning of human societies, all forms of healers and healthcare providers have been involved in the process of diagnosis in one form or another. As science has advanced in its understanding of causes of death and illness, procedures for diagnosis have also evolved. The procedures and rules for making diagnoses in many areas of healthcare continue to evolve as new technology and research develop. Technologies take many forms, ranging from improved questionnaires to new interview procedures, automated tests and screening online, the use of new imaging technologies, and even the use of diagnostic micro- or nano-robots that can enter the body and allow diagnosticians to see what is happening inside specific organs. All these methods aid in quicker diagnoses and faster paths to effective treatment.

One challenge to evolving diagnostic methods is that the world continually becomes more interconnected. As a result, it is important for diagnosticians of all types to recognize cultural differences in terms of how symptoms are experienced, expressed, and understood. This is true for both physical and mental health problems. Therefore, relevant screening, assessment, and other diagnostic technologies may need to be adjusted in terms of both how early symptoms are identified and how information about diagnoses is conveyed to individuals of different backgrounds. While diagnosis does involve technology, it is also a procedure involving human communication. As definitions and understandings of illness and health vary by culture, communications surrounding diagnoses must also adjust among healthcare providers.

Bibliography

Doherty, Gerard M., editor. Current Diagnosis & Treatment: Surgery. 15th ed. McGraw-Hill Education, 2020.

Helman, Cecil G. Culture, Health and Illness: An Introduction for Health Professionals. 2nd ed. Elsevier Science, 2014.

International Statistical Classification of Diseases and Related Health Problems. 11th rev., 2022 version, World Health Organization, 2023, www.who.int/standards/classifications/classification-of-diseases. Accessed 20 July 2023.

Porter, Robert S., and Justin L. Kaplan, editors. The Merck Manual of Diagnosis and Therapy. 20th ed., Merck Sharp & Dohme, 2018.