Skip to main content
Select Source:

Diagnosis

Diagnosis

Diagnosis is the process of identifying a disease or disorder in a person by examining the person and studying the results of medical tests.

The process of diagnosis begins when a patient appears before a doctor with a set of symptoms, such as pain, nausea, fever, or some other unusual feeling. In many cases, the diagnosis is relatively simple. The physician can decide by making a few simple observations as to the patient's problem and can prescribe a proper treatment. At other times, the symptoms may be more difficult to interpret, and making a diagnosis may require laboratory tests and other kinds of examinations.

Sources of information

In order to make a diagnosis, a physician searches for information from three major sources: the patient himself or herself, a physical examination, and a laboratory examination.

Patient information. Patient information is obtained by asking the patient a variety of questions about his or her previous health history and present symptoms. For example, the patient who is experiencing unusual pains may be asked to tell how long the pains have persisted, where they are located, the type of pain experienced, and whether the pain is constant or intermittent.

Words to Know

Benign: Noncancerous.

Biopsy: The removal and examination of tissue from a person's body.

Invasive: A technique that involves entering the body.

Laparoscope: A device consisting of a long flexible tube that contains a light source that allows a physician to look into the abdominal cavity without making a large incision in the abdominal wall.

Laparotomy: A process by which the abdominal wall is opened in order to allow a physician to look inside.

Malignant: Cancerous.

Palpation: A technique used by doctors that involves the use of fingers to touch and feel various parts of a patient's body.

Stethoscope: A device that magnifies sounds produced in the human body.

A patient's occupation may have a bearing on his or her illness. Perhaps he or she works around chemicals that may cause illness. A job that requires repeated bending and lifting may result in muscle strain or back pain. A police officer or fire fighter may have periods of boredom interrupted by periods of stress or fear.

The medical history of a patient's family may also be helpful. Some diseases are hereditary and some, although not hereditary, are more likely to occur if the patient's parent or other close relative has had such a disease. For example, the person whose father has had a heart attack is more likely to have a heart attack than is a person whose family has been free of heart disease.

Personal habits, such as smoking or drinking large amounts of alcohol, also contribute to disease. Lack of exercise, lack of sleep, and an unhealthy diet are all involved in bringing about symptoms of disease.

The physical examination. In addition to exploring the patient's clinical history, the physician will carry out a physical examination to further narrow the list of possible medical problems. The patient's temperature, blood pressure, and rate of respiration will be measured. He or she will be weighed and his or her height measured. The physician will examine the eardrums and look into the throat for signs of inflammation, infection, or other abnormal conditions.

The heart and lungs can be examined superficially (from outside the body) using a stethoscope. A stethoscope allows the physician to hear abnormalities in the heartbeat or in the functioning of the heart valves. The presence of water or other fluid in the lungs can also be heard with a stethoscope. The physician can also study sounds made by the intestines by listening to them through the stethoscope.

A physician may also use a technique called palpation, in which the physician uses his or her fingers to probe the abdomen for signs of pain or an abnormal lump or growth. The doctor also feels the neck, the area under the armpit, and other areas to locate any enlarged lymph nodes, a sign of an infection. Such probing also may bring to light the presence of a tender area previously unknown to the patient.

If the patient is complaining of an injury, the physician can carefully palpate around the injury to determine its size. He or she can bend a leg or arm to determine whether a joint has been broken. Similar techniques also reveal whether a ligament (tissue that connects bones) has been torn and if it may need surgical correction.

The laboratory examination. The physician also may decide to have laboratory tests performed on various fluids taken from the patient. The most common fluids used are blood, urine, stomach fluid, and spinal fluid. As an example, tests of the blood reveal the number of white and red blood cells. An elevated number of white blood cells indicates an infection is present, but does not pinpoint the location of the infection. Blood also carries hormones and other components that are directly affected by disease or inflammation.

The modern clinical laboratory is one of automation and high technology. At one time, a laboratory technician was required to mix together the chemicals needed for each clinical test. Newer technology requires only that a blood specimen be placed in one end of a machine. The blood is carried through the machine, where minute amounts of the chemicals are added as needed, and test results are printed out automatically. This technology also enables the measurement of blood or urine components in amounts much smaller than previous technology allowed. In some cases, a single microgram (one-millionth of a gram) can be detected in blood, urine or some other fluid.

The physician also may want to obtain X rays of an injured area to rule out the possibility of a fractured bone. (X rays are a form of electromagnetic radiation that can penetrate solids. They are used to generate images of bones and other tissues.) The presence of a heart condition can often be determined by taking an electrocardiogram (ECG), which measures the electrical activity of the heart. Changes in an ECG can indicate the presence of heart disease or give evidence of a past heart attack. CAT (computerized axial tomography) scans use X rays to produce images of one layer of hard or soft tissue, a procedure useful in detecting small

tumors. Magnetic resonance imaging (MRI) uses radio waves in a magnetic field to generate images of a layer of the brain, heart, or other organ. Ultrasound waves are also sometimes used to detect tumors.

Other laboratory specimens can be obtained by invasive techniques. An invasive technique is one in which a physician cuts open the body to look directly inside it for possible medical problems. For example, a physician who finds a suspicious lump or swelling can remove part of the lump and send it to the laboratory to be examined. The surgical removal of tissue for testing is called a biopsy. In the laboratory, the specimen is sliced very thinly, dyed to highlight differences in tissues, and examined under the microscope. This procedure enables the physician to determine whether the lump is malignant (cancerous) or benign (noncancerous).

The method of actually looking into the body cavity used to consist of a major surgical procedure called a laparotomy. In that procedure, an incision is made in the abdomen so the physician can look at each organ and other internal structures in order to determine the presence of disease or a parasite. Today, the laparotomy is carried out using a flexible tube called a laparoscope. The laparoscope is inserted into the body through a small incision. It is attached to a television monitor that gives the physician an enlarged view of the inside of the body. The flexibility of the laparoscope allows the instrument to be guided around the organs. A light attached to the scope helps the physician see each organ. The laparoscope is also equipped with a tiny device to collect specimens or to suction blood out of the abdomen.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"Diagnosis." UXL Encyclopedia of Science. . Encyclopedia.com. 20 Sep. 2018 <http://www.encyclopedia.com>.

"Diagnosis." UXL Encyclopedia of Science. . Encyclopedia.com. (September 20, 2018). http://www.encyclopedia.com/science/encyclopedias-almanacs-transcripts-and-maps/diagnosis-1

"Diagnosis." UXL Encyclopedia of Science. . Retrieved September 20, 2018 from Encyclopedia.com: http://www.encyclopedia.com/science/encyclopedias-almanacs-transcripts-and-maps/diagnosis-1

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.

Diagnosis

Diagnosis

Definition

Diagnosis can be defined as the identification and labeling of a disease based on its signs and symptoms. Mental health clinicians (psychiatrists, psychologists, and psychiatric nurse practitioners) diagnose mental disorders using the criteria listed in the Diagnostic and Statistical Manual of Mental Disorders , also known as the DSM, published by the American Psychiatric Association.

Description

According to the DSM, fourth edition, text revised (the DSM-IV-TR ), the term mental disorder is unfortunate because it implies that a mental disorder is separate from a physical illness, when actually, according to the American Psychiatric Association (APA), researchers and scientists now know that that distinction is not a clear one to make. The APA argues that "there is much 'physical' in 'mental disorders' and much 'mental' in 'physical disorders,'" and continues to use the term "mental disorders" because a better term has not yet been found. The APA defines a mental disorder as "a clinically significant behavioral or psychological syndrome or pattern that occurs in an individual and that is associated with present distress or disability or with a significantly increased risk of suffering death, pain, disability, or an important loss of freedom." Many people fear that when a mental disorder is classified, people are actually classified, and the DSM-IV-TR strives to contradict this notion. The American Psychiatric Association believes their manual to be strictly a manual classifying mental disorders themselves, and does not advocate the use of the diagnoses to discriminate.

The manual lists various criteria for each mental disorder included in the book. When an individual seeks the help of a mental health clinician, the clinician interviews the client (along with family members when appropriate), gathers a medical history, and may administer psychological evaluations (various checklists or tests that the patient may complete) in order to establish a diagnosis. Once the clinician has gathered the necessary information, a diagnosis based on the symptoms may be assigned from the DSM.

One of the main purposes of diagnosis is to guide treatment planning. If doctors know that a particular disorder has shown to be treated effectively with a drug or with a specific therapy, then the best practice can be applied to a new case of that disorder. The diagnosis also helps to establish a prognosis for the patient and his or her family, and it helps to enable communication among the professionals (including insurers) involved in a patient's care. Additionally, a formal diagnosis as recognized by the DSM may be necessary in order for insurers to pay for medical services. The act of labeling a mental disorder may have unintended effects for the person with the disorder, however. Although the DSM states that its diagnoses do not label people, in reality, many people who have received diagnoses of mental disorders may feel affected by the label their disorder has been given. People diagnosed with mental disorders may feel stigmatized, and that others' perceptions of themas well as their self-perceptions have changed as a result of their diagnosis.

See also Assessment and diagnosis; Stigma

Resources

BOOKS

Allen, John J. B. "DSM-IV." In Encyclopedia of Mental Health, edited by Howard S. Friedman. San Diego, CA: Academic Press, 1998.

American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. Fourth edition, text revised. Washington DC: American Psychiatric Association, 2000.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"Diagnosis." Gale Encyclopedia of Mental Disorders. . Encyclopedia.com. 20 Sep. 2018 <http://www.encyclopedia.com>.

"Diagnosis." Gale Encyclopedia of Mental Disorders. . Encyclopedia.com. (September 20, 2018). http://www.encyclopedia.com/psychology/encyclopedias-almanacs-transcripts-and-maps/diagnosis

"Diagnosis." Gale Encyclopedia of Mental Disorders. . Retrieved September 20, 2018 from Encyclopedia.com: http://www.encyclopedia.com/psychology/encyclopedias-almanacs-transcripts-and-maps/diagnosis

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.

diagnosis

diagnosis, determination of the nature of a disease or ailment. A clinical diagnosis is based on the medical history and physical examination of the patient: it may be confirmed with X-Rays, CAT Scans (Computerized Axial Tomography), MRI (Magnetic Resonance Imaging), and other laboratory tests. Diagnosis by physical examination includes ascertaining temperature, pulse, and blood pressure and involves the use of palpation, to detect enlarged organs and other abnormalities; tapping, to delineate some of the internal organs; and listening, to interpret sounds from organs such as the heart and lungs. Instruments that facilitate physical examination include the sphygmomanometer for blood pressure; the stethoscope for listening to the heart and lungs; the ophthalmoscope to examine the inner eye; and the laryngoscope and bronchoscope to view the larynx, windpipe, and other air passages. Recent innovations in electronics have made it possible for any of these devices to be fitted with video cameras and lights, so that the interior of the body can be viewed on video monitors and recorded on videotape for future reference. In diagnostic tests, the blood, urine, tissues, and other excretions and secretions of the body are examined for evidence of chemical imbalance, cellular change, and the presence of pathogenic organisms. Exploratory surgery and the insertion of visual equipment through a small incision (e.g., laparoscopy and arthroscopy) may be used to assist in diagnosis.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"diagnosis." The Columbia Encyclopedia, 6th ed.. . Encyclopedia.com. 20 Sep. 2018 <http://www.encyclopedia.com>.

"diagnosis." The Columbia Encyclopedia, 6th ed.. . Encyclopedia.com. (September 20, 2018). http://www.encyclopedia.com/reference/encyclopedias-almanacs-transcripts-and-maps/diagnosis

"diagnosis." The Columbia Encyclopedia, 6th ed.. . Retrieved September 20, 2018 from Encyclopedia.com: http://www.encyclopedia.com/reference/encyclopedias-almanacs-transcripts-and-maps/diagnosis

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.

diagnosis

diagnosis (dy-ăg-noh-sis) n. the process of determining the nature of a disorder by considering the patient's signs and symptoms, medical background, and – when necessary – results of laboratory tests and X-ray examinations. differential d. diagnosis of a condition whose signs and/or symptoms are shared by various other conditions. See also prenatal diagnosis. Compare prognosis.
diagnostic (dy-ăg-noss-tik) adj.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"diagnosis." A Dictionary of Nursing. . Encyclopedia.com. 20 Sep. 2018 <http://www.encyclopedia.com>.

"diagnosis." A Dictionary of Nursing. . Encyclopedia.com. (September 20, 2018). http://www.encyclopedia.com/caregiving/dictionaries-thesauruses-pictures-and-press-releases/diagnosis

"diagnosis." A Dictionary of Nursing. . Retrieved September 20, 2018 from Encyclopedia.com: http://www.encyclopedia.com/caregiving/dictionaries-thesauruses-pictures-and-press-releases/diagnosis

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.

diagnosis

di·ag·no·sis / ˌdīəgˈnōsis/ • n. (pl. -ses / -ˌsēz/ ) 1. the identification of the nature of an illness or other problem by examination of the symptoms: early diagnosis and treatment are essential | a diagnosis of Crohn's disease was made. 2. the distinctive characterization in precise terms of a genus, species, or phenomenon.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"diagnosis." The Oxford Pocket Dictionary of Current English. . Encyclopedia.com. 20 Sep. 2018 <http://www.encyclopedia.com>.

"diagnosis." The Oxford Pocket Dictionary of Current English. . Encyclopedia.com. (September 20, 2018). http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/diagnosis-0

"diagnosis." The Oxford Pocket Dictionary of Current English. . Retrieved September 20, 2018 from Encyclopedia.com: http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/diagnosis-0

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.

diagnosis

diagnosis XVII. — modL. — Gr. diāgnōsis, f. diagignṓskein distinguish, discern, f. DIA- + gignṓskein perceive (see KNOW).

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"diagnosis." The Concise Oxford Dictionary of English Etymology. . Encyclopedia.com. 20 Sep. 2018 <http://www.encyclopedia.com>.

"diagnosis." The Concise Oxford Dictionary of English Etymology. . Encyclopedia.com. (September 20, 2018). http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/diagnosis-1

"diagnosis." The Concise Oxford Dictionary of English Etymology. . Retrieved September 20, 2018 from Encyclopedia.com: http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/diagnosis-1

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.

diagnosis

diagnosisglacis, Onassis •abscess •anaphylaxis, axis, praxis, taxis •Chalcis • Jancis • synapsis • catharsis •Frances, Francis •thesis • Alexis • amanuensis •prolepsis, sepsis, syllepsis •basis, oasis, stasis •amniocentesis, anamnesis, ascesis, catechesis, exegesis, mimesis, prosthesis, psychokinesis, telekinesis •ellipsis, paralipsis •Lachesis •analysis, catalysis, dialysis, paralysis, psychoanalysis •electrolysis • nemesis •genesis, parthenogenesis, pathogenesis •diaeresis (US dieresis) • metathesis •parenthesis •photosynthesis, synthesis •hypothesis, prothesis •crisis, Isis •proboscis • synopsis •apotheosis, chlorosis, cirrhosis, diagnosis, halitosis, hypnosis, kenosis, meiosis, metempsychosis, misdiagnosis, mononucleosis, myxomatosis, necrosis, neurosis, osmosis, osteoporosis, prognosis, psittacosis, psychosis, sclerosis, symbiosis, thrombosis, toxoplasmosis, trichinosis, tuberculosis •archdiocese, diocese, elephantiasis, psoriasis •anabasis • apodosis •emphasis, underemphasis •anamorphosis, metamorphosis •periphrasis • entasis • protasis •hypostasis, iconostasis

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"diagnosis." Oxford Dictionary of Rhymes. . Encyclopedia.com. 20 Sep. 2018 <http://www.encyclopedia.com>.

"diagnosis." Oxford Dictionary of Rhymes. . Encyclopedia.com. (September 20, 2018). http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/diagnosis

"diagnosis." Oxford Dictionary of Rhymes. . Retrieved September 20, 2018 from Encyclopedia.com: http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/diagnosis

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.

Diagnosis

Diagnosis

Definition

Description

Resources

Definition

Diagnosis can be defined as the identification and labeling of a disease based on its signs and symptoms. Mental health clinicians (psychiatrists, psychologists, and psychiatric nurse practitioners) diagnose mental disorders using the criteria listed in the Diagnostic and Statistical Manual of Mental Disorders, also known as the DSM, published by the American Psychiatric Association (APA).

Description

According to the DSM, fourth edition, text revised (the DSM-IV-TR), the term mental disorder is unfortunate because it implies that a mental disorder is separate from a physical illness, when actually, according to the APA, researchers and scientists now know that that distinction is not a clear one to make. The APA argues that “there is much ‘physical’ in ‘mental disorders’ and much ‘mental’ in ‘physical disorders,”’ and continues to use the term “mental disorders” because a better term has not yet been found. The APA defines a mental disorder as “a clinically significant behavioral or psychological syndrome or pattern that occurs in an individual and that is associated with present distress or disability or with a significantly increased risk of suffering death, pain, disability, or an important loss of freedom.” Many people fear that when a mental disorder is classified, people are actually classified, and the DSMIV-TR strives to contradict this notion. The APA believes their manual to be strictly a manual classifying mental disorders themselves, and does not advocate the use of the diagnoses to discriminate.

The manual lists various criteria for each mental disorder included in the book. When an individual seeks the help of a mental health clinician, the clinician interviews the client (along with family members when appropriate), gathers a medical history, and may administer psychological evaluations (various checklists or tests that the patient may complete) in order to establish a diagnosis. Once the clinician has gathered the necessary information, a diagnosis based on the symptoms may be assigned from the DSM.

One of the main purposes of diagnosis is to guide treatment planning. If doctors know that a particular disorder has shown to be treated effectively with a drug or with a specific therapy, then the best practice can be applied to a new case of that disorder. The diagnosis also helps to establish a prognosis for the patient and his or her family, and it helps to enable communication among the professionals (including insurers) involved in a patient’s care. Additionally, a formal diagnosis as recognized by the DSM may be necessary in order for insurers to pay for medical services. The act of labeling a mental disorder may have unintended effects for the person with the disorder, however. Although the DSM states that its diagnoses do not label people, in reality, many people who have received diagnoses of mental disorders may feel affected by the label their disorder has been given. People diagnosed with mental disorders may feel stigmatized, and that others’ perceptions of them—as well as their self-perceptions—have changed as a result of their diagnosis.

See alsoAssessment and diagnosis; Stigma.

Resources

BOOKS

Allen, John J. B. “DSM-IV.” In Encyclopedia of Mental Health, edited by Howard S. Friedman. San Diego, CA: Academic Press, 1998.

American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. Fourth edition, text revised. Washington DC: American Psychiatric Association, 2000.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"Diagnosis." The Gale Encyclopedia of Mental Health. . Encyclopedia.com. 20 Sep. 2018 <http://www.encyclopedia.com>.

"Diagnosis." The Gale Encyclopedia of Mental Health. . Encyclopedia.com. (September 20, 2018). http://www.encyclopedia.com/medicine/encyclopedias-almanacs-transcripts-and-maps/diagnosis

"Diagnosis." The Gale Encyclopedia of Mental Health. . Retrieved September 20, 2018 from Encyclopedia.com: http://www.encyclopedia.com/medicine/encyclopedias-almanacs-transcripts-and-maps/diagnosis

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.

Diagnosis

Diagnosis

Patient information

The physical examination

The laboratory examination

Diagnosis, from gnosis, the Greek word for knowledge, is the process of identifying a disease or disorder in a person by examining the person through a physical examination and studying the results of medical tests and laboratory and radiological techniques.

The diagnosis, in the field of medicine, begins when the patient is presented to the doctor with a set of symptoms or perceived abnormalities such as pain, nausea, fever, or other untoward feeling. Often the diagnosis is relatively simple, and the physician can arrive at a clinical conclusion and prescribe the proper treatment. At other times, the symptoms may be subtle and seemingly unrelated, making the diagnosis difficult to finalize and requiring laboratory work.

The diagnosis is based on data the physician obtains from three sources, the first being the patient. This includes the patients perception of his or her symptoms, medical history, family history, occupation, and other relevant facts. The physician then narrows the diagnosis with a second set of information obtained from the physical examination of the patient. The third source is the data obtained from medical tests, such as a blood test, x ray, or an electrocardiogram.

Patient information

The physician begins the examination by asking about the patients symptoms. The patient may be asked to describe the symptoms and how long he or she has been experiencing them. If the patient is in pain, information is collected about the location, type, and duration of the pain. Other symptoms that may be present but may not have been noticed by the patient must be explored.

The patients occupation may have a bearing on his or her illness. Perhaps he or she works around chemicals that may cause illness. A job of repetitive bending and lifting may result in muscle strain or back pain. A police officer or fire fighter may have periods of boredom interrupted by periods of stress or fear.

The physician must learn when the symptoms first appeared and whether they have worsened over time or remained the same in intensity. If the patient has more than one symptom, the physician must know which appeared first and in what order the others appeared. The doctor will also ask if the symptoms are similar to ones the patient has experienced in the past or if they are entirely new.

The medical history of the patients family also may be helpful. Some diseases are hereditary and some, though not hereditary, are more likely to occur if the patients parent or other close relative has had such a disease. For example, the person whose father has had a heart attack is more likely to have a heart attack than is a person whose family has been free of heart disease.

Personal habits, such as smoking or drinking large amounts of alcohol, also contribute to disease. Lack of exercise, lack of sleep, and an unhealthy diet are all involved in bringing about symptoms of disease.

The physical examination

In addition to exploring the patients clinical history, the physician will carry out a physical examination to further narrow the list of possible conditions. The patients temperature, blood pressure, and rate of respiration will be measured. He or she will be weighed and his or her height measured. The physician will use an otoscope to examine the eardrums and to look into the throat for signs of inflammation, infection, or other abnormal conditions.

The heart and lungs can be examined superficially using a stethoscope. Abnormalities in the heartbeat or in the functioning of the heart valves can be heard in this way, and the presence of water or other fluid in the lungs can be heard as noises called rales. The physician also can study the sounds made by the intestines by listening to them through the stethoscope.

Using his/her fingers, a technique called palpation, the physician probes the abdomen for signs of pain or an abnormal lump or growth. He/she also feels the neck, the axillary area (armpit) and other locales to locate any enlarged lymph nodes, a sign of an infection. Such probing also may bring to light the presence of a tender area previously unknown to the patient.

If the patient is complaining of an injury, the physician can carefully palpate around the injury to determine its size. He/she can bend an leg or arm to assess the integrity of the joint. Using other maneuvers, the physician can determine whether a ligament has been torn and if it may need surgical correction.

The laboratory examination

Having learned the patients clinical history and made his/her physical examination, the physician may then decide to submit specimens from the patient to a laboratory for testing. Fluids such as blood, urine, stomach fluid, or spinal fluid can be collected.

Basic laboratory tests of blood include a count of the number of white and red blood cells. An elevated number of white blood cells indicates an infection is present, but does not pinpoint the location of the infection. Blood also carries hormones and other components that are directly affected by disease or inflammation.

Far from the laboratory of the 1960s, the modern clinical laboratory is one of automation and high technology. Whereas before the laboratory technician was required to mix together the chemicals for each test, newer technology requires only that a blood specimen be placed in one end of a machine. The blood is carried through the machine, minute amounts of the chemicals are added as needed, and the results printed out. This technology also enables the measurement of blood or urine components in amounts much smaller than previous technology allowedoften at microgram levels. (A microgram is one millionth of a gram.) To measure such a minute amount, the chemistry involved is precise and the reading of the results is beyond the capability of the human eye.

Both blood and urine may contain evidence of alcohol, illicit drugs, or toxic substances that the patient has taken. Infectious organisms from the blood or urine can be grown in culture dishes and examined to determine what they are. Bacteria in blood or urine are often too sparsely distributed to be seen under the microscope, but bacteria in a blood specimen wiped across a plate of culture medium will grow when the plate is placed in an incubator at body temperature.

The physician also may want to obtain x rays of an injured area to rule out the possibility of a fractured bone. The presence of a heart condition can often be determined by taking an electrocardiogram (ECG), which measures the electrical activity of the heart. Changes in the ECG can indicate the presence of heart disease or give evidence of a past heart attack. CAT (computerized axial tomography) scans use x rays to produce images of one layer of hard or soft tissue, a procedure useful in detecting small tumors. Magnetic resonance imaging (MRI) uses radio waves in a magnetic field to generate images of a layer of the brain, heart, or other organ. Ultrasound waves are also sometimes used to detect tumors.

Physicians can collect other kinds of information by injecting substances into the patient. Injection of radiopaque liquids, which block the passage of x rays, allow x-ray examination of soft tissues, such as the spinal cord, that are normally undetectable on x-ray photographs. Metabolic disorders can sometimes be pinpointed using a procedure called scintigraphy, in which a radioactive isotope is circulated through the body. A gamma camera is then used to record the concentration of the isotope in various tissues and organs.

KEY TERMS

Culture medium A substance that supports the growth of bacteria so they may be identified.

Invasive A technique that involves entering the body.

Pathology The study of changes in body tissues brought about by disease or injury.

other laboratory specimens can be obtained by invasive techniques. If the physician finds a suspicious lump or swelling and needs to know its nature, he or she can remove part of the lump and send it to the laboratory to be examined. The surgical removal of tissue for testing is called a biopsy. In the laboratory, the specimen is sliced very thin, dyed to accentuate differences in tissues, and examined under the microscope. This enables the physician to determine whether the lump is malignant (cancerous) or benign (noncancerous). If it is cancer, further tests can determine if it is the primary tumor or if it has grown (metastasis) as a result of being spread from the primary tumor. Other tests can determine what kind of cancer it is.

The method of actually looking into the body cavity used to mean a major surgical procedure called a laparotomy. In that procedure, an incision was made in the abdomen so the physician could look at each organ and other internal structure in order and determine the presence of disease or parasite. Now the laparotomy is carried out using a flexible scope called a laparoscope, which is inserted into the body through a small incision. The scope is attached to a television monitor that gives the physician an enlarged view of the inside of the body. The flexibility of the scope allows it to be guided around the organs, and a light attached to the scope helps the physician see each organ. In addition, the laparoscope is equipped with the means to collect biopsy specimens or suction blood out of the abdomen. Minor surgery can also be carried out to stop a bleeding blood vessel or remove a small growth from an organ.

Once the above steps the physician deems necessary have been carried out, he or she will then study the evidence collectively and arrive at a diagnosis. Once having determined the diagnosis, the physician can prescribe the proper treatment.

Larry Blaser

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"Diagnosis." The Gale Encyclopedia of Science. . Encyclopedia.com. 20 Sep. 2018 <http://www.encyclopedia.com>.

"Diagnosis." The Gale Encyclopedia of Science. . Encyclopedia.com. (September 20, 2018). http://www.encyclopedia.com/science/encyclopedias-almanacs-transcripts-and-maps/diagnosis

"Diagnosis." The Gale Encyclopedia of Science. . Retrieved September 20, 2018 from Encyclopedia.com: http://www.encyclopedia.com/science/encyclopedias-almanacs-transcripts-and-maps/diagnosis

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.

Diagnosis

Diagnosis

Diagnosis, from gnosis, the Greek word for knowledge, is the process of identifying a disease or disorder in a person by examining the person and studying the results of medical tests.

The diagnosis begins when the patient is presented to the doctor with a set of symptoms or perceived abnormalities such as pain , nausea, fever, or other untoward feeling. Often the diagnosis is relatively simple, and the physician can arrive at a clinical conclusion and prescribe the proper treatment. At other times, the symptoms may be subtle and seemingly unrelated, making the diagnosis difficult to finalize and requiring laboratory work.

The diagnosis is based on data the physician obtains from three sources, the first being the patient. This includes the patient's perception of his or her symptoms, medical history, family history, occupation, and other relevant facts. The physician then narrows the diagnosis with a second set of information obtained from the physical examination of the patient. The third source is the data obtained from medical tests, such as a blood test, x ray, or an electrocardiogram.


Patient information

The physician begins the examination by asking about the patient's symptoms. The patient may be asked to describe the symptoms and how long he or she has been experiencing them. If the patient is in pain, information is collected about the location, type, and duration of the pain. Other symptoms that may be present but may not have been noticed by the patient must be explored.

The patient's occupation may have a bearing on his or her illness. Perhaps he or she works around chemicals that may cause illness. A job of repetitive bending and lifting may result in muscle strain or back pain. A police officer or fire fighter may have periods of boredom interrupted by periods of stress or fear.

The physician must learn when the symptoms first appeared and whether they have worsened over time or remained the same in intensity. If the patient has more than one symptom, the physician must know which appeared first and in what order the others appeared. The doctor will also ask if the symptoms are similar to ones the patient has experienced in the past or if they are entirely new.

The medical history of the patient's family also may be helpful. Some diseases are hereditary and some, though not hereditary, are more likely to occur if the patient's parent or other close relative has had such a disease. For example, the person whose father has had a heart attack is more likely to have a heart attack than is a person whose family has been free of heart disease.

Personal habits, such as smoking or drinking large amounts of alcohol , also contribute to disease. Lack of exercise , lack of sleep , and an unhealthy diet are all involved in bringing about symptoms of disease.


The physical examination

In addition to exploring the patient's clinical history, the physician will carry out a physical examination to further narrow the list of possible conditions. The patient's temperature , blood pressure , and rate of respiration will be measured. He or she will be weighed and his or her height measured. The physician will use an otoscope to examine the eardrums and to look into the throat for signs of inflammation , infection , or other abnormal conditions.

The heart and lungs can be examined superficially using a stethoscope. Abnormalities in the heartbeat or in the functioning of the heart valves can be heard in this way, and the presence of water or other fluid in the lungs can be heard as noises called rales. The physician also can study the sounds made by the intestines by listening to them through the stethoscope.

Using his fingers, a technique called palpation, the physician probes the abdomen for signs of pain or an abnormal lump or growth. He also feels the neck, the axillary area (armpit) and other locales to locate any enlarged lymph nodes, a sign of an infection. Such probing also may bring to light the presence of a tender area previously unknown to the patient.

If the patient is complaining of an injury, the physician can carefully palpate around the injury to determine its size. He can bend an leg or arm to assess the integrity of the joint. Using other maneuvers, he can determine whether a ligament has been torn and if it may need surgical correction.


The laboratory examination

Having learned the patient's clinical history and made his physical examination, the physician may then decide to submit specimens from the patient to a laboratory for testing. Fluids such as blood, urine, stomach fluid, or spinal fluid can be collected.

Basic laboratory tests of blood include a count of the number of white and red blood cells. An elevated number of white blood cells indicates an infection is present, but does not pinpoint the location of the infection. Blood also carries hormones and other components that are directly affected by disease or inflammation.

Far from the laboratory of the 1960s, the modern clinical laboratory is one of automation and high technology. Whereas before the laboratory technician was required to mix together the chemicals for each test, newer technology requires only that a blood specimen be placed in one end of a machine. The blood is carried through the machine and minute amounts of the chemicals are added as needed and the results printed out. This technology also enables the measurement of blood or urine components in amounts much smaller than previous technology allowed—often at microgram levels. A microgram is one millionth of a gram. To measure such a minute amount, the chemistry involved is precise and the reading of the results is beyond the capability of the human eye .

Both blood and urine may contain evidence of alcohol, illicit drugs, or toxic substances that the patient has taken. Infectious organisms from the blood or urine can be grown in culture dishes and examined to determine what they are. Bacteria in blood or urine are often too sparsely distributed to be seen under the microscope , but bacteria in a blood specimen wiped across a plate of culture medium will grow when the plate is placed in an incubator at body temperature.

The physician also may want to obtain x rays of an injured area to rule out the possibility of a fractured bone. The presence of a heart condition can often be determined by taking an electrocardiogram (ECG) , which measures the electrical activity of the heart. Changes in the ECG can indicate the presence of heart disease or give evidence of a past heart attack. CAT (computerized axial tomography ) scans use x rays to produce images of one layer of hard or soft tissue , a procedure useful in detecting small tumors. Magnetic resonance imaging (MRI) uses radio waves in a magnetic field to generate images of a layer of the brain , heart, or other organ . Ultrasound waves are also sometimes used to detect tumors.

Physicians can collect other kinds of information by injecting substances into the patient. Injection of radiopaque liquids, which block the passage of x rays, allow x-ray examination of soft tissues, such as the spinal cord, that are normally undetectable on x-ray photographs. Metabolic disorders can sometimes be pinpointed using a procedure called scintigraphy, in which a radioactive isotope is circulated through the body. A gamma camera is then used to record the concentration of the isotope in various tissues and organs.

Other laboratory specimens can be obtained by invasive techniques. If the physician finds a suspicious lump or swelling and needs to know its nature, he can remove part of the lump and send it to the laboratory to be examined. The surgical removal of tissue for testing is called a biopsy. In the laboratory, the specimen is sliced very thin, dyed to accentuate differences in tissues, and examined under the microscope. This enables the physician to determine whether the lump is malignant (cancerous) or benign (noncancerous). If it is cancer , further tests can determine if it is the primary tumor or if it has grown (metastasis) as a result of being spread from the primary tumor. Other tests can determine what kind of cancer it is.

The method of actually looking into the body cavity used to mean a major surgical procedure called a laparotomy. In that procedure, an incision was made in the abdomen so the physician could look at each organ and other internal structure in order and determine the presence of disease or parasite. Now the laparotomy is carried out using a flexible scope called a laparoscope, which is inserted into the body through a small incision. The scope is attached to a television monitor that gives the physician an enlarged view of the inside of the body. The flexibility of the scope allows it to be guided around the organs, and a light attached to the scope helps the physician see each organ. Also, the laparoscope is equipped with the means to collect biopsy specimens or suction blood out of the abdomen. Minor surgery can also be carried out to stop a bleeding blood vessel or remove a small growth from an organ.

Once the above steps the physician deems necessary have been carried out, he or she will then study the evidence collectively and arrive at a diagnosis. Once having determined the diagnosis, he or she can prescribe the proper treatment.

Larry Blaser

KEY TERMS

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Culture medium

—A substance that supports the growth of bacteria so they may be identified.

Invasive

—A technique that involves entering the body.

Pathology

—The study of changes in body tissues brought about by disease or injury.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"Diagnosis." The Gale Encyclopedia of Science. . Encyclopedia.com. 20 Sep. 2018 <http://www.encyclopedia.com>.

"Diagnosis." The Gale Encyclopedia of Science. . Encyclopedia.com. (September 20, 2018). http://www.encyclopedia.com/science/encyclopedias-almanacs-transcripts-and-maps/diagnosis-0

"Diagnosis." The Gale Encyclopedia of Science. . Retrieved September 20, 2018 from Encyclopedia.com: http://www.encyclopedia.com/science/encyclopedias-almanacs-transcripts-and-maps/diagnosis-0

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.