Medical diagnosis: Difference between revisions

Diagnosis is a major component of the [[Doctor's visit#Procedure|procedure of a doctor's visit]]. From the point of view of [[statistics]], the diagnostic procedure involves [[classification test]]s.

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.)

Even during an already ongoing diagnostic procedure, there can be an indication to perform another, separate, diagnostic procedure for another, potentially concomitant, disease or condition. This may occur as a result of an [[incidental finding]] of a sign unrelated to the parameter of interest, such as can occur in comprehensive tests such as [[radiology|radiological]] studies like [[magnetic resonance imaging]] or [[blood test]] panels that also include blood tests that are not relevant for the ongoing diagnosis.

General components which are present in a diagnostic procedure in most of the various available methods include:

* Complementing the already given information with further data gathering, which may include questions of the [[medical history]] (potentially from other people close to the patient as well), [[physical examination]] and various [[diagnostic test]]s.<br> A diagnostic test is any kind of [[medical test]] performed to aid in the diagnosis or detection of disease. Diagnostic tests can also be used to provide prognostic information on people with established disease.

There are a number of methods or techniques that can be used in a diagnostic procedure, including performing a [[differential diagnosis]] or following [[medical algorithm]]s. In reality, a diagnostic procedure may involve components of multiple methods.

{{Main|Differential diagnosis}}

The method of differential diagnosis is based on finding as many candidate diseases or conditions as possible that can possibly cause the signs or symptoms, followed by a [[process of elimination]] or at least of rendering the entries more or less probable by further [[medical test]]s and other processing, aiming to reach the point where only one candidate disease or condition remains as probable. The result may also remain a list of possible conditions, ranked in order of probability or severity. Such a list is often generated by computer-aided diagnosis systems.

If unexpected findings are made during this process, the initial [[hypothesis]] may be ruled out and the provider must then consider other hypotheses.

In a [[pattern recognition]] method the provider uses experience to recognize a pattern of clinical characteristics. It is mainly based on certain symptoms or signs being [[Association (psychology)|associated]] with certain diseases or conditions, not necessarily involving the more cognitive processing involved in a differential diagnosis.

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.

{{Main|Clinical case definition}}

The term ''diagnostic criteria'' designates the specific combination of [[signs and symptoms]], and test results that the [[clinician]] uses to attempt to determine the correct diagnosis.

* [[Centor criteria]] for [[Streptococcal pharyngitis|strep throat]]

[[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. 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.

Other methods that can be used in performing a diagnostic procedure include:

[[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]].]]

* An "exhaustive method", in which every possible question is asked and all possible data is collected.

Diagnosis problems are the dominant cause of medical malpractice payments, accounting for 35% of total payments in a study of 25 years of data and 350,000 claims.

{{Main|Overdiagnosis}}

Overdiagnosis is the diagnosis of "disease" that will never cause symptoms or death during a patient's lifetime. It is a problem because it turns people into patients unnecessarily and because it can lead to economic waste ([[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.

{{Further|Medical error}}

Most people will experience at least one diagnostic error in their lifetime, according to a 2015 report by the [[National Academies of Sciences, Engineering, and Medicine]].

* the condition has a rare [[wikt:presentation|presentation]]

When making a medical diagnosis, a lag time is a delay in time until a step towards [[diagnosis]] of a disease or condition is made. Types of lag times are mainly:

* ''Onset-to-medical encounter lag time'', the time from onset of [[symptom]]s until visiting a [[health care provider]]

Long lag times are often called "diagnostic odyssey".

{{Main|History of medical diagnosis}}

The first recorded examples of medical diagnosis are found in the writings of [[Imhotep]] (2630–2611 BC) in [[ancient Egypt]] (the [[Edwin Smith Papyrus]]). 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]]. [[Traditional Chinese Medicine]], as described in the Yellow Emperor's Inner Canon or [[Huangdi Neijing]], specified four diagnostic methods: inspection, auscultation-olfaction, interrogation,  and [[palpation]]. [[Hippocrates]] was known to make diagnoses by tasting his patients' urine and smelling their sweat.

{{Main|Wiktionary:diagnosis}}

Medical diagnosis or the actual process of making a diagnosis is a cognitive process. A clinician uses several sources of data and puts the pieces of the puzzle together to make a diagnostic impression. The initial diagnostic impression can be a broad term describing a category of diseases instead of a specific disease or condition. After the initial diagnostic impression, the clinician obtains follow up tests and procedures to get more data to support or reject the original diagnosis and will attempt to narrow it down to a more specific level. Diagnostic procedures are the specific tools that the clinicians use to narrow the diagnostic possibilities.

The plural of diagnosis is ''diagnoses''. The verb is ''to diagnose, ''and a person who diagnoses is called a ''diagnostician''.

The word ''[[wikt: diagnosis|diagnosis]]'' {{IPAc-en|d|aɪ|.|ə|ɡ|ˈ|n|oʊ|s|ᵻ|s}} is derived through [[Latin]] from the [[Ancient Greek|Greek]] word διάγνωσις (''diágnōsis'') from διαγιγνώσκειν (''diagignṓskein''), meaning "to discern, distinguish".

=== Social context ===

Diagnosis can take many forms. It might be a matter of naming the disease, lesion, dysfunction or disability. It might be a management-naming or prognosis-naming exercise. It may indicate either degree of abnormality on a continuum or kind of abnormality in a classification. It's influenced by non-medical factors such as power, ethics and financial incentives for patient or doctor. It can be a brief summation or an extensive formulation, even taking the form of a story or metaphor. It might be a means of communication such as a computer code through which it triggers payment, prescription, notification, information or advice. It might be [[pathogenic]] or [[salutogenic]]. It's generally uncertain and provisional.

* might reduce the likelihood that some fearful patients will go-by the treatment.

Sub-types of diagnoses include:

:The labeling of an illness in a historical figure or specific historical event using modern knowledge, methods and disease classifications.

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* [[Diagnosis code]]s

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* [[List of diagnostic classification and rating scales used in psychiatry]]

* [[List of diseases]]

* [[:Category:Diseases]]

{{wiktionary|diagnosis}}

* {{Commons category-inline|Medical diagnosis}}