Medical diagnosis: Difference between revisions

'''Medical diagnosis''' (abbreviated '''Dx''',<ref>See ''[[List of medical abbreviations: D]]'' for variants.</ref> '''D_x''', or '''D_s''') is the process of determining which [[disease]] or condition explains a person's [[symptom]]s and [[medical sign|signs]]. It is most often referred to as a '''diagnosis''' with the [[medicine|medical]] context being implicit. The information required for a diagnosis is typically collected from a [[medical history|history]] and [[physical examination]] of the person seeking medical care. Often, one or more '''diagnostic procedures''', such as [[medical test]]s, are also done during the process. Sometimes the [[posthumous diagnosis]] is considered a kind of medical diagnosis.

Diagnosis is often challenging because many signs and symptoms are [[sensitivity and specificity|nonspecific]]. For example, redness of the [[Human skin|skin]] ([[erythema]]), by itself, is a sign of many disorders and thus does not tell the healthcare professional what is wrong. Thus [[differential diagnosis]], in which several possible explanations are compared and contrasted, must be performed. This involves the [[correlation]] of various pieces of information followed by the recognition and differentiation of patterns. Occasionally the process is made easy by a sign or symptom (or a group of several) that is [[pathognomonic]].{{cn|date=March 2024}}

A diagnosis, in the sense of diagnostic procedure, can be regarded as an attempt at classification of an individual's condition into separate and distinct categories that allow medical decisions about treatment and prognosis to be made. Subsequently, a diagnostic opinion is often described in terms of a disease or other condition. (In the case of a wrong diagnosis, however, the individual's actual disease or condition is not the same as the individual's diagnosis.) A total evaluation of a condition is often termed a diagnostic workup.<ref name="MW">{{cite web |title=Definition of workup |url=https://www.merriam-webster.com/dictionary/workup |website=www.merriam-webster.com |access-date=30 January 2024 |language=en}}</ref>

A diagnostic procedure may be performed by various [[healthcare professional]]s such as a [[physician]], [[chiropractor]], [[physiotherapist]], [[dentist]], [[podiatrist]], [[optometrist]], [[nurse practitioner]], [[Healthcare science|healthcare scientist]] or [[physician assistant]]. This article uses ''diagnostician'' as any of these person categories.{{cn|date=March 2024}}

A diagnostic procedure (as well as the opinion reached thereby) does not necessarily involve elucidation of the [[etiology (medicine)|etiology]] of the diseases or conditions of interest, that is, what ''caused'' the disease or condition. Such elucidation can be useful to optimize treatment, further specify the prognosis or prevent recurrence of the disease or condition in the future.{{cn|date=March 2024}}

The initial task is to detect a [[Indication (medicine)|medical indication]] to perform a diagnostic procedure. Indications include:{{cn|date=March 2024}}

The resultant diagnostic opinion by this method can be regarded more or less as a [[diagnosis of exclusion]]. Even if it does not result in a single probable disease or condition, it can at least rule out any imminently life-threatening conditions.{{cn|date=March 2024}}

Unless the provider is certain of the condition present, further medical tests, such as medical imaging, are performed or scheduled in part to confirm or disprove the diagnosis but also to document the patient's status and keep the patient's medical history up to date.{{cn|date=March 2024}}

If unexpected findings are made during this process, the initial [[hypothesis]] may be ruled out and the provider must then consider other hypotheses.{{cn|date=March 2024}}

This may be the primary method used in cases where diseases are "obvious", or the provider's experience may enable him or her to recognize the condition quickly. Theoretically, a certain pattern of signs or symptoms can be directly associated with a certain therapy, even without a definite decision regarding what is the actual disease, but such a compromise carries a substantial risk of missing a diagnosis which actually has a different therapy so it may be limited to cases where no diagnosis can be made.{{cn|date=March 2024}}

[[Clinical decision support system]]s are interactive computer programs designed to assist health professionals with decision-making tasks. The clinician interacts with the software utilizing both the clinician's knowledge and the software to make a better analysis of the patients data than either human or software could make on their own. Typically the system makes suggestions for the clinician to look through and the clinician picks useful information and removes erroneous suggestions.<ref>Decision support systems. 26 July 2005. 17 Feb. 2009 <http://www.openclinical.org/dss.html {{Webarchive|url=https://web.archive.org/web/20200202124813/http://www.openclinical.org/dss.html |date=2020-02-02 }}></ref> Some programs attempt to do this by replacing the clinician, such as reading the output of a heart monitor. Such automated processes are usually deemed a "device" by the FDA and require regulatory approval. In contrast, clinical decision support systems that "support" but do not replace the clinician are deemed to be "Augmented Intelligence" if it meets the FDA criteria that (1) it reveals the underlying data, (2) reveals the underlying logic, and (3) leaves the clinician in charge to shape and make the decision.{{cn|date=March 2024}}

[[File:Assessment and treatment algorithm for overweight and obesity.png|thumb|350px|An example of a medical algorithm for assessment and treatment of [[overweight]] and [[obesity]].]]

Overdiagnosis is the diagnosis of "disease" that will never cause symptoms or death during a patient's lifetime.<ref>{{cite book |title=What is overdiagnosis? |url=https://www.ncbi.nlm.nih.gov/books/NBK430655/ |website=NCBI|date=20 April 2017 |publisher=Institute for Quality and Efficiency in Health Care (IQWiG) }}</ref> It is a problem because it turns people into patients unnecessarily and because it can lead to economic waste<ref>{{cite journal |last1=Coon |first1=Eric |last2=Moyer |first2=Virginia |last3=Schroeder |first3=Alan |last4=Quinonez |first4=Ricardo |title=Overdiagnosis: How Our Compulsion for Diagnosis May Be Harming Children |url= https://pediatrics.aappublications.org/content/134/5/1013 |journal=Pediatrics|year=2014 |volume=134 |issue=5 |pages=1013–23 |doi=10.1542/peds.2014-1778 |pmid=25287462 |s2cid=10441386 |doi-access=free }}</ref> ([[overutilization]]) and treatments that may cause harm. Overdiagnosis occurs when a disease is diagnosed correctly, but the diagnosis is irrelevant. A correct diagnosis may be irrelevant because treatment for the disease is not available, not needed, or not wanted.<ref>{{cite magazine |last1=Gawande |first1=Atul |title=America's Epidemic of Unnecessary Care |url=https://www.newyorker.com/magazine/2015/05/11/overkill-atul-gawande |magazine=The New Yorker|date=4 May 2015 }}</ref>

The first recorded examples of medical diagnosis are found in the writings of [[Imhotep]] (2630–2611 BC) in [[ancient Egypt]] (the [[Edwin Smith Papyrus]]).<ref>{{Cite web|url = https://www.britannica.com/EBchecked/topic/179901/Edwin-Smith-papyrus|title = Edwin Smith Papyrus|access-date = 2015-02-28}}</ref> A [[Babylonia]]n medical textbook, the ''Diagnostic Handbook'' written by [[Esagil-kin-apli]] ([[floruit|fl.]]1069–1046 BC), introduced the use of [[empiricism]], [[logic]] and [[rationality]] in the diagnosis of an illness or [[disease]].<ref>H. F. J. Horstmanshoff, Marten Stol, Cornelis Tilburg (2004), ''Magic and Rationality in Ancient Near Eastern and Graeco-Roman Medicine'', pp. 97–98, [[Brill Publishers]], {{ISBN|90-04-13666-5}}.</ref> [[Traditional Chinese Medicine]], as described in the Yellow Emperor's Inner Canon or [[Huangdi Neijing]], specified four diagnostic methods: inspection, auscultation-olfaction, interrogation, inquiry and [[palpation]].<ref>{{Cite book | last1 = Jingfeng | first1 = C. | title = Encyclopaedia of the History of Science, Technology, and Medicine in Non-Western Cultures | doi = 10.1007/978-1-4020-4425-0_8500 | pages = 1529–34 | year = 2008 | chapter = Medicine in China | isbn = 978-1-4020-4559-2 }}</ref> [[Hippocrates]] was known to make diagnoses by tasting his patients' urine and smelling their sweat.<ref>{{Cite web|url = http://well.blogs.nytimes.com/2008/09/23/what-would-hippocrates-do/|title = What Would Hipocrates Do?|date = 23 September 2008|access-date = February 28, 2015}}</ref>

Once a diagnostic opinion has been reached, the provider is able to propose a management plan, which will include treatment as well as plans for follow-up. From this point on, in addition to treating the patient's condition, the provider can educate the patient about the [[etiology]], progression, [[prognosis]], other outcomes, and possible treatments of her or his ailments, as well as providing advice for maintaining health.{{cn|date=March 2024}}

A treatment plan is proposed which may include therapy and follow-up consultations and tests to [[monitoring (medicine)|monitor]] the condition and the progress of the treatment, if needed, usually according to the medical guidelines provided by the medical field on the treatment of the particular illness.{{cn|date=March 2024}}

[[Nancy McWilliams]] identifies five reasons that determine the necessity for diagnosis:

* might reduce the likelihood that some fearful patients will go-by the treatment.<ref>{{cite book|title=Psychoanalytic Diagnosis|last=McWilliams |first=Nancy |title=Psychoanalytic Diagnosis |publisher=[[Guilford Press]] |year=2011 |isbn=978-1-60918-494-0 |edition=2nd |page=8 |author-link=Nancy McWilliams}}</ref>

:A diagnosis made on the basis of [[medical sign]]s and reported [[symptom]]s, rather than [[diagnostic test]]s{{cn|date=March 2024}}

:A diagnosis based significantly on laboratory reports or test results, rather than the [[physical examination]] of the patient. For instance, a proper diagnosis of infectious diseases usually requires both an examination of signs and symptoms, as well as laboratory test results and characteristics of the pathogen involved.{{cn|date=March 2024}}

:A diagnosis based primarily on the results from [[medical imaging]] studies. [[Greenstick fracture]]s are common radiological diagnoses.{{cn|date=March 2024}}

:A diagnosis based on measurement and recording of electrophysiologic activity.{{cn|date=March 2024}}

:A diagnosis based on the macroscopic, microscopic, and molecular examination of tissues such as biopsies or whole organs. For example, a definitive diagnosis of [[cancer]] is made via tissue examination by a [[pathologist]].{{cn|date=March 2024}}

:The single medical diagnosis that is most relevant to the patient's [[chief complaint]] or need for treatment. Many patients have additional diagnoses.{{cn|date=March 2024}}

:The diagnosis of two related, but separate, medical conditions or [[comorbidities]]. The term almost always referred to a diagnosis of a serious mental illness and a substance use disorder, however, the increasing prevalence of [[genetic testing]] has revealed many cases of patients with multiple concomitant genetic disorders.<ref name="dualddx">{{cite journal|author1=Wadhwa, R. R.|author2=Park, D. Y.|author3=Natowicz, M. R.|title=The accuracy of computer‐based diagnostic tools for the identification of concurrent genetic disorders|journal=American Journal of Medical Genetics Part A|volume=176|issue=12|pages=2704–09|doi=10.1002/ajmg.a.40651|pmid=30475443|year=2018|s2cid=53758271}}</ref>

:Providing [[symptoms]] allows the computer to identify the problem and [[diagnose]] the user to the best of its ability.<ref>{{cite journal|author1=Berner, E. S.|author2=Webster, G. D.|author3=Shugerman, A. A.|author4=Jackson, J. R.|author5=Algina, J.|author6=Baker, A. L.|author7=Ball, E.V.|author8=Cobbs, C. G.|author9=Dennis, V. W.|display-authors=3 |title=Performance of four computer-based diagnostic systems|journal=New England Journal of Medicine|year=1994|volume=330|issue=25|pages=1792–96 |doi=10.1056/NEJM199406233302506|pmid=8190157|doi-access=free}}</ref><ref name="dualddx"/> Health screening begins by identifying the part of the body where the symptoms are located; the computer cross-references a database for the corresponding [[disease]] and presents a diagnosis.<ref>{{cite web | url= http://www.webmedicine.ca | title= Connection between onset of symptoms and diagnosis | author= WebMed Solutions | access-date= 15 January 2012 | archive-url= https://web.archive.org/web/20190213000314/https://www.webmedicine.ca/ | archive-date= 13 February 2019 | url-status= dead }}</ref>

* [[Misdiagnosis]] and [[medicalMedical error]]