Editing Blood test

{{short description|Laboratory analysis performed on a blood sample}}
{{for|the novel by Jonathan Kellerman|Blood Test (novel)}}
[[File:Hematology .jpg|thumb|Modern hospital hematology laboratory]]

A '''blood test''' is a [[medical laboratory|laboratory]] analysis performed on a [[blood]] sample that is usually extracted from a [[vein]] in the arm using a [[hypodermic needle]], or via [[fingerprick]]. Multiple tests for specific blood components, such as a [[glucose test]] or a [[cholesterol test]], are often grouped together into one [[test panel]] called a '''blood panel''' or '''blood work'''. Blood tests are often used in [[health care]] to determine [[physiological]] and [[biochemical]] states, such as [[disease]], [[mineral]] content, [[pharmaceutical drug]] effectiveness, and organ function. Typical [[medicine#Clinical practice|clinical]] blood panels include a [[basic metabolic panel]] or a [[complete blood count]]. Blood tests are also used in [[drug test]]s to detect drug abuse.

==Extraction==
[[Image:Blooddraw.jpg|thumb|right|A [[venipuncture]] performed using a [[vacutainer]]]]
A [[venipuncture]] is useful as it is a [[Invasiveness of surgical procedures|minimally invasive]] way to obtain [[cell (biology)|cell]]s and [[extracellular fluid]] ([[blood plasma|plasma]]) from the body for analysis. Blood flows throughout the body, acting as a medium that provides [[oxygen]] and nutrients to tissues and carries waste products back to the excretory systems for disposal. Consequently, the state of the bloodstream affects or is affected by, many medical conditions. For these reasons, blood tests are the most commonly performed [[medical test]]s.<ref>{{Cite web |title=Venipuncture - the extraction of blood using a needle and syringe |url=https://www.nlm.nih.gov/medlineplus/ency/article/003423.htm |url-status=live |archive-url=https://web.archive.org/web/20120621165102/http://www.nlm.nih.gov/medlineplus/ency/article/003423.htm |archive-date=June 21, 2012 |access-date=June 21, 2012}}</ref>

If only a few drops of blood are needed, a [[fingerstick]] is performed instead of a [[venipuncture]].<ref name="pmid17630562">{{Cite journal |vauthors=MacLennan CA, van Oosterhout JJ, White SA, Drayson MT, Zijlstra EE, Molyneux ME |date=July 2007 |title=Finger-prick blood samples can be used interchangeably with venous samples for CD4 cell counting indicating their potential for use in CD4 rapid tests |journal=AIDS |volume=21 |issue=12 |pages=1643–5 |doi=10.1097/QAD.0b013e32823bcb03 |pmc=2408852 |pmid=17630562}}</ref>

Indwelling arterial, central venous and peripheral venous lines can also be used to draw blood.<ref>{{Cite journal |last=Lesser |first=Finnian D |last2=Lanham |first2=David A |last3=Davis |first3=Daniel |date=6 May 2020 |title=Blood sampled from existing peripheral IV cannulae yields results equivalent to venepuncture: a systematic review |journal=JRSM Open |volume=11 |issue=5 |pages=205427041989481 |doi=10.1177/2054270419894817 |pmc=7236571 |pmid=32523703 |doi-access=free}}</ref>

[[Phlebotomist]]s, [[medical laboratory|laboratory practitioners]] and [[nurse]]s are those in charge of extracting blood from a patient. However, in special circumstances, and/or emergency situations, [[paramedic]]s and [[physician]]s extract the blood. Also, [[respiratory therapist]]s are trained to extract arterial blood to examine [[arterial blood gas]]es.<ref>{{Cite journal |vauthors=Aaron SD, Vandemheen KL, Naftel SA, Lewis MJ, Rodger MA |year=2003 |title=Topical tetracaine prior to arterial puncture: a randomized, placebo-controlled clinical trial |journal=Respir. Med. |volume=97 |issue=11 |pages=1195–1199 |doi=10.1016/S0954-6111(03)00226-9 |pmid=14635973 |doi-access=free}}</ref><ref>{{Cite web |date=2010-01-05 |title=Michigan careers |url=http://www.michigan.gov/careers/0,1607,7-170-46398-64537--,00.html |url-status=dead |archive-url=https://web.archive.org/web/20110629044218/http://www.michigan.gov/careers/0%2C1607%2C7-170-46398-64537--%2C00.html |archive-date=June 29, 2011 |access-date=2011-08-09 |publisher=Michigan.gov}}</ref>

==Types of tests==
[[File:Vacutainer blood bottles.jpg|thumb|[[Vacutainer]] tubes used in the collection of blood. During venipuncture, pressure differences between the vein and the vacuum in the Vacutainer forces blood into the tube.]]

===Biochemical analysis===
A [[basic metabolic panel]] measures [[sodium]], [[potassium]], [[chloride]], [[bicarbonate]], [[blood urea nitrogen]] (BUN), [[magnesium]], [[creatinine]], [[glucose]], and sometimes [[calcium]]. Tests that focus on cholesterol levels can determine [[LDL cholesterol|LDL]] and [[HDL cholesterol]] levels, as well as [[triglyceride]] levels.<ref>{{Cite web |last=Belargo |first=Kevin |title=Cholesterol Levels |url=http://ldlhdlcholesterollevels.org/ |url-status=live |archive-url=https://web.archive.org/web/20120118114849/http://ldlhdlcholesterollevels.org/ |archive-date=18 January 2012 |access-date=17 January 2012 |publisher=Manic EP}}</ref>

Some tests, such as those that measure glucose or a [[lipid profile]], require fasting (or no food consumption) eight to twelve hours prior to the drawing of the blood sample.<ref>{{Cite web |title=Fasting blood samples |url=http://www.nhs.uk/chq/Pages/1018.aspx?CategoryID=69&SubCategoryID=693 |url-status=live |archive-url=https://web.archive.org/web/20120621000111/http://www.nhs.uk/chq/Pages/1018.aspx?CategoryID=69&SubCategoryID=693 |archive-date=June 21, 2012 |access-date=June 21, 2012 |publisher=NHS UK}}</ref>

For the majority of tests, blood is usually obtained from the patient's vein. Other specialized tests, such as the [[arterial blood gas]] test, require blood extracted from an [[artery]]. Blood gas analysis of arterial blood is primarily used to monitor [[carbon dioxide]] and [[oxygen]] levels related to [[pulmonary]] function, but is also used to measure blood [[pH]] and [[bicarbonate]] levels for certain metabolic conditions.<ref>{{Cite web |title=Blood gases |url=http://www.nhs.uk/conditions/blood-gases-test/Pages/Introduction.aspx |url-status=live |archive-url=https://web.archive.org/web/20120506082818/http://www.nhs.uk/conditions/blood-gases-test/Pages/Introduction.aspx |archive-date=May 6, 2012 |access-date=June 21, 2012 |publisher=NHS UK}}</ref>

While the regular [[glucose test]] is taken at a certain point in time, the [[glucose tolerance test]] involves repeated testing to determine the rate at which [[glucose]] is processed by the body.<ref>{{Cite web |title=Glucose tolerance test |url=https://www.nlm.nih.gov/medlineplus/ency/article/003466.htm |url-status=live |archive-url=https://web.archive.org/web/20120609040705/http://www.nlm.nih.gov/medlineplus/ency/article/003466.htm |archive-date=June 9, 2012 |access-date=June 21, 2012 |publisher=Medline}}</ref>

Blood tests are also used to identify autoimmune diseases and [[Immunoglobulin E]]-mediated food allergies (see also [[Radioallergosorbent test]]).<ref>{{Cite book |url=https://www.worldcat.org/oclc/77830546 |title=Handbook of nutrition and food |date=2008 |publisher=Taylor & Francis |others=Carolyn D. Berdanier, Johanna T. Dwyer, Elaine B. Feldman |isbn=978-0-8493-9218-4 |edition=2 |location=Boca Raton |oclc=77830546}}</ref>{{Rp|page=1118}}

====Normal ranges====
{{Main|Reference ranges for blood tests}}
Blood tests results should always be interpreted using the ranges provided by the laboratory that performed the test. Example ranges are shown below.
{| class="wikitable"
 !Test<ref>C. A. Burtis and E. R. Ashwood, ''Tietz Textbook of Clinical Chemistry'' (1994) 2nd edition, {{ISBN|0-7216-4472-4}}</ref><ref>{{Cite web |title=Blood tests normal ranges |url=http://www.empr.com/reference-values-for-commonly-ordered-blood-tests/article/123621/ |url-status=live |archive-url=https://web.archive.org/web/20180621070222/http://www.empr.com/reference-values-for-commonly-ordered-blood-tests/article/123621/ |archive-date=June 21, 2018 |access-date=June 21, 2012 |publisher=Monthly Prescribing Reference}}</ref>|| Low || High || Unit || Comments
 |-
 | [[Sodium]] (Na) || 134 || 145 || mmol/L ||
 |-
 | [[Potassium]] (K) || 3.5 || 5.0 || mmol/L ||
 |-
 | [[Urea]] || 2.5 || 6.4 || mmol/L || [[Blood urea nitrogen]] (BUN)
 |-
 | Urea || 15 || 40 || mg/dL ||
 |-
 | [[Creatinine]] - male || 62 || 115 || μmol/L ||
 |-
 | Creatinine - female || 53 || 97 || μmol/L ||
 |-
 | Creatinine - male || 0.7 || 1.3 || mg/dL ||
 |-
 | Creatinine - female || 0.6 || 1.2
 || mg/dL ||
 |-
 | [[Blood sugar|Glucose]] (fasting) || 3.9 || 5.8 || mmol/L || ''See also'' [[glycated hemoglobin]]
 |-
 | Glucose (fasting) || 70 || 120 || mg/dL ||
 |-
 |}

====Common abbreviations====
Upon completion of a blood test analysis, patients may receive a report with blood test abbreviations. Examples of common blood test abbreviations are shown below.
{| class="wikitable"
!Abbreviation<ref>{{Cite web |title=Appendix B: Some Common Abbreviations |url=https://www.nlm.nih.gov/medlineplus/appendixb.html |url-status=live |archive-url=https://web.archive.org/web/20160425091357/https://www.nlm.nih.gov/medlineplus/appendixb.html |archive-date=2016-04-25 |access-date=2016-04-16 |website=MedlinePlus |publisher=U.S. National Library of Medicine}}</ref><ref>{{Cite web |title=Understanding Blood Tests Online |url=https://www.labtestsportal.com/online-blood-test/ |url-status=dead |archive-url=https://web.archive.org/web/20160409214339/https://www.labtestsportal.com/online-blood-test/ |archive-date=2016-04-09 |access-date=2016-04-16 |website=Lab Tests Portal}}</ref>
!Stands for
!Description
|-
|HDL
|[[High Density Lipoprotein]]
|Level of "good cholesterol" in the blood (ratio of HDL:LDL is usually more significant than actual values)
|-
|LDL
|[[Low Density Lipoprotein]]
|Level of "bad cholesterol" in the blood (ratio of HDL:LDL is usually more significant than actual values)
|-
|PV
|[[Hyperviscosity syndrome|Plasma Viscosity]]
|Plasma Viscometry (PV) is the measurement of the viscosity of blood plasma. The result is a number given in milliPascal seconds (m.Pas.s) – known as the PV, or plasma viscosity.
|-
|CRP
|[[C-Reactive Protein]]
|Level of inflammation with the body. If the immune system is fighting an infection or illness, CRP will be higher.
|-
|CBC
(UK: FBC)
|[[Complete Blood Count]]
(UK: Full Blood Count)
|Analysis of 15 different blood test readings to provide information about overall health.
|-
|TSH
|[[Thyroid-stimulating hormone]]
|Thyroid regulates the function of metabolism. Low levels can lead to weight loss, while high levels lead to weight gain.
|-
|PTH
|[[Parathyroid hormone]]
|Regulates [[Calcium in biology|serum calcium]]
|-
|ESR
|[[Erythrocyte Sedimentation Rate]]
|Indicates the time it takes for red blood cells to move down a tube. This shows signs of inflammation within a body.
|-
|INR
|[[International Normalized Ratio]]
|This is a blood clotting test.
|-
|LFT
|Liver Function Test
|This test reveals the levels of waste products, enzymes and proteins that are processed by the liver.
|-
|U+E
|Urea and Electrolytes
|This test is performed to measure the function of kidney.
|-
|CMP
|[[Comprehensive Metabolic Panel]]
|This analysis provides an overall picture of the metabolism and chemical balance of the body.
|-
|WBC
|[[White Blood Cell]] Count
|The level of white blood cells.
|-
|RBC
|[[Red Blood Cell]] Count
|The level of red blood cells.
|-
|HBC
|[[Hemoglobin]]
|Level of hemoglobin molecules.
|-
|HCT
|[[Hematocrit]]
|Similar to RBC but in percentage.
|-
|PLT
|[[Platelets]]
|Platelets levels in the blood.
|}

===Molecular profiles===
* [[Protein electrophoresis]] (general technique—not a specific test)
* [[Western blot]] (general technique—not a specific test)
* [[Liver function tests]]
* [[Polymerase chain reaction]] (DNA). [[DNA profiling]] is today possible with even very small quantities of blood: this is commonly used in [[forensic science]], but is now also part of the diagnostic process of many disorders.
* [[Northern blot]] (RNA)
* [[Sexually transmitted disease]]s

===Cellular evaluation===
* [[Full blood count]] (or "Complete Blood Count")
* [[Hematocrit]]
* [[Mean corpuscular volume|MCV]] ("Mean Corpuscular Volume")
* [[Mean corpuscular hemoglobin concentration]] (MCHC)
* [[Erythrocyte sedimentation rate]] (ESR)
* [[Cross-matching]]. Determination of [[blood type]] for [[blood transfusion]] or [[Organ transplant|transplants]]
* [[Blood culture]]s are commonly taken if infection is suspected. Positive cultures and resulting sensitivity results are often useful in guiding medical treatment.

==Future alternatives==
===Saliva tests===
In 2008, scientists announced that the more cost effective [[saliva testing]] could eventually replace some blood tests, as saliva contains 20% of the proteins found in blood.<ref>{{Cite journal |display-authors=etal |vauthors=Denny P, Hagen FK, Hardt M |date=May 2008 |title=The proteomes of human parotid and submandibular/sublingual gland salivas collected as the ductal secretions |journal=J. Proteome Res. |volume=7 |issue=5 |pages=1994–2006 |doi=10.1021/pr700764j |pmc=2839126 |pmid=18361515}}</ref> Saliva testing may not be appropriate or available for all markers. For example, lipid levels cannot be measured with saliva testing.

===Microemulsion===
In February 2011, Canadian researchers at the University of Calgary's Schulich School of Engineering announced a microchip for blood tests. Dubbed a microemulsion, a droplet of blood captured inside a layer of another substance. It can control the exact size and spacing of the droplets. The new test could improve the efficiency, accuracy, and speed of laboratory tests while also doing it cheaply.<ref>{{Cite news |date=2 February 2011 |title=Microchip offers faster and cheaper way to test blood |url=http://www.ctvnews.ca/microchip-offers-faster-and-cheaper-way-to-test-blood-1.605318 |url-status=live |archive-url=https://web.archive.org/web/20161003103102/http://www.ctvnews.ca/microchip-offers-faster-and-cheaper-way-to-test-blood-1.605318 |archive-date=3 October 2016 |access-date=2 October 2016 |work=CTV News |agency=Bell Media}}</ref>

===SIMBAS===
In March 2011, a team of researchers from [[University of California, Berkeley|UC Berkeley]], [[Dublin City University|DCU]] and [[University of Valparaíso]] have developed [[lab-on-a-chip]] that can diagnose diseases within 10 minutes without the use of external tubing and extra components. It is called Self-powered Integrated Microfluidic Blood Analysis System (SIMBAS). It uses tiny trenches to separate blood cells from plasma (99 percent of blood cells were captured during experiments). Researchers used plastic components, to reduce manufacturing costs.<ref>{{Cite web |last=Taylor |first=Kate |date=2011-03-18 |title=Blood analysis chip detects diseases in minutes |url=http://www.tgdaily.com/general-sciences-features/54744-blood-analysis-chip-detects-diseases-in-minutes |url-status=dead |archive-url=https://web.archive.org/web/20110325092922/http://www.tgdaily.com/general-sciences-features/54744-blood-analysis-chip-detects-diseases-in-minutes |archive-date=2011-03-25 |access-date=2011-03-26}}</ref><ref>{{Cite web |last=Dailey |first=Jessica |date=2011-03-22 |title=New SIMBAS Blood Analysis Biochip Can Diagnose Diseases In Minutes |url=http://inhabitat.com/new-simbas-blood-analysis-biochip-can-diagnose-diseases-in-minutes/ |url-status=live |archive-url=https://web.archive.org/web/20110326025327/http://inhabitat.com/new-simbas-blood-analysis-biochip-can-diagnose-diseases-in-minutes |archive-date=2011-03-26 |access-date=2011-03-26 |publisher=Inhabitat.com}}</ref>

==See also==
* [[Barbro Hjalmarsson]]
* [[Biomarker (medicine)]], a protein or other biomolecule measured in a blood test
* [[Blood film]], a way to look at blood cells under a microscope
* [[Blood gas test]]
* [[Blood lead level]]
* [[Hematology]], the study of blood
* [[Luminol]], a visual test for blood left at crime scenes.
* [[Reference ranges for blood tests]]
* [[Schumm test]], a common test for blood mismatch
* [[:Category:Blood tests]]
* [[List of medical tests]]

==References==
{{reflist}}

{{Clinical biochemistry blood tests}}
{{Myeloid blood tests}}
{{Infectious and inflammatory blood tests}}

{{Authority control}}

[[Category:Blood tests| ]]