What is a medical diagnosis?

Indications and Procedures

When individuals see health care 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. They 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 and for which additional assessment is needed. Screening is inexpensive and involves 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 there 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, and 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. The most common diagnostic systems in use are the Diagnostic and Statistical Manual of Mental Disorders: DSM-5 (rev. 5th ed., 2013), and the International Classification of Diseases
(2011).

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 (using more to get the same effect), withdrawal (insomnia when stopping using), 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, however, is that some diagnoses have symptoms that overlap and that methods of differential diagnoses are always developing. As such, it is possible for misdiagnoses to occur. When this occurs, individuals may be treated for the wrong problem, or even overdiagnosed or underdiagnosed, and thus not properly treated. As such, it is often advised for more serious conditions that are costly to treat for patients to use multiple methods of diagnosis and even seek secondary opinions to confirm the diagnosis.

Perspective and Prospects

All forms of healers and health care providers have been involved, since the beginning human societies, 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 health care continue to evolve as new technology and research develop. New technologies take many forms, ranging from improved questionnaires, to new interview procedures, to automated tests and screening online, to the use of new magnetic resonance imaging (MRI), and to even the use of virtual reality-assisted robots entering the body and allowing 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 has become more interconnected over the last century. 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 adjust both in terms of how early symptoms are identified and in how information about diagnoses is conveyed to individuals of different backgrounds. This is the case as well because while diagnosis does involve technology, it is also a procedure involving human communication. As definitions and understandings of illness and health vary by culture, so too will communications about diagnosis need to adjust as cultures and health care providers interact more and more.

Bibliography

American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders: DSM-5. Rev. 5th ed. Washington, DC: Author, 2013.

Doherty, Gerard M., and Lawrence W. Way. Current Surgical Diagnosis and Treatment. 13th ed. New York: Lange Medical/McGraw-Hill, 2010.

Helman, Cecil G., ed. Culture, Health, and Illness. 5th ed. London: Hodder Education, 2007.

Merck Research Laboratories. The Merck Manual of Diagnosis and Therapy. 19th ed. Whitehouse Station: Author, 2011.

World Health Organization. International Statistical Classification of Diseases and Related Health Problems: 10th Revision–ICD-10. 2010 ed. Geneva, Switzerland: Author, 2011.