Medical diagnosis
Medical diagnosis is the process of determining which disease or condition explains a person's symptoms and signs. It is most often referred to as diagnosis with the medical context being implicit. The information required for diagnosis is typically collected from a history and physical examination of the person seeking medical care. Often, one or more diagnostic procedures, such as medical tests, are also done during the process. Sometimes posthumous diagnosis is considered a kind of medical diagnosis.
Diagnosis is often challenging, because many signs and symptoms are nonspecific. For example, redness of the skin, 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 that is pathognomonic.
Diagnosis is a major component of the procedure of a doctor's visit. From the point of view of statistics, the diagnostic procedure involves classification tests.
Medical uses
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.A diagnostic procedure may be performed by various healthcare professionals such as a physician, physiotherapist, dentist, podiatrist, optometrist, nurse practitioner, healthcare scientist or physician assistant. This article uses diagnostician as any of these person categories.
A diagnostic procedure does not necessarily involve elucidation of the 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.
The initial task is to detect a medical indication to perform a diagnostic procedure. Indications include:
- Detection of any deviation from what is known to be normal, such as can be described in terms of, for example, anatomy, physiology, pathology, psychology and human homeostasis. Knowledge of what is normal and measuring of the patient's current condition against those norms can assist in determining the patient's particular departure from homeostasis and the degree of departure, which in turn can assist in quantifying the indication for further diagnostic processing.
- A complaint expressed by a patient.
- The fact that a patient has sought a diagnostician can itself be an indication to perform a diagnostic procedure. For example, in a doctor's visit, the physician may already start performing a diagnostic procedure by watching the gait of the patient from the waiting room to the doctor's office even before she or he has started to present any complaints.
Procedure
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, physical examination and various diagnostic tests.
- Processing of the answers, findings or other results. Consultations with other providers and specialists in the field may be sought.
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 tests and other processing, aiming to reach the point where only one candidate disease or condition remains as probable. The final 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.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.
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.
If unexpected findings are made during this process, the initial hypothesis may be ruled out and the provider must then consider other hypotheses.
Pattern recognition
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 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.
Diagnostic criteria
The term diagnostic criteria designates the specific combination of signs, symptoms, and test results that the clinician uses to attempt to determine the correct diagnosis.Some examples of diagnostic criteria, also known as clinical case definitions, are:
- Amsterdam criteria for hereditary nonpolyposis colorectal cancer
- McDonald criteria for multiple sclerosis
- ACR criteria for systemic lupus erythematosus
- Centor criteria for strep throat
Clinical decision support system
Other diagnostic procedure methods
Other methods that can be used in performing a diagnostic procedure include:and obesity.
- Usage of medical algorithms
- An "exhaustive method", in which every possible question is asked and all possible data is collected. This is often referred to as a diagnostic workup.
- Use of a sensory pill that collects and transmits physiological information after being swallowed.
- Using optical coherence tomography to produce detailed images of the brain or other soft tissue, through a "window" made of zirconia that has been modified to be transparent and implanted in the skull.
Adverse effects
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 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.Errors
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.Causes and factors of error in diagnosis are:
- the manifestation of disease are not sufficiently noticeable
- a disease is omitted from consideration
- too much significance is given to some aspect of the diagnosis
- the condition is a rare disease with symptoms suggestive of many other conditions
- the condition has a rare
Lag time
- Onset-to-medical encounter lag time, the time from onset of symptoms until visiting a health care provider
- Encounter-to-diagnosis lag time, the time from first medical encounter to diagnosis
- *Lag time due to delays in reading x-rays have been cited as a major challenge in care delivery. The Department of Health and Human Services has reportedly found that interpretation of x-rays is rarely available to emergency room physicians prior to patient discharge.
History
Word
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.
Etymology
The word is derived through Latin from the Greek word διάγνωσις from διαγιγνώσκειν, meaning "to discern, distinguish".Society and culture
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.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.
A treatment plan is proposed which may include therapy and follow-up consultations and tests to 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.
Relevant information should be added to the medical record of the patient.
A failure to respond to treatments that would normally work may indicate a need for review of the diagnosis.
Nancy McWilliams identifies five reasons that determine the necessity for diagnosis:
- diagnosis for treatment planning;
- information contained in it related to prognosis;
- protecting interests of patients;
- a diagnosis might help the therapist to empathize with his patient;
- might reduce the likelihood that some fearful patients will go-by the treatment.
Types
;Clinical diagnosis
;Laboratory diagnosis
;Radiology diagnosis
;Tissue diagnosis
;Principal diagnosis
;Admitting diagnosis
;Differential diagnosis
;Diagnostic criteria
;Prenatal diagnosis
;Diagnosis of exclusion
;Dual diagnosis
;Self-diagnosis
;Remote diagnosis
;Nursing diagnosis
;Computer-aided diagnosis
;Overdiagnosis
;Wastebasket diagnosis
;Retrospective diagnosis