Biomarkers · Chemical
C-Reactive Protein, Quant
A c-reactive protein test measures the level of c-reactive protein (CRP) in a sample of your blood. Your liver makes CRP in response to inflammation.
C-Reactive Protein (CRP) Test, MedlinePlus, National Library of Medicine
C-reactive protein is a protein the liver makes in response to inflammation in the body. CRP levels rise and fall with the amount of inflammation in the body.
- Primary unit
- mg/L
- LOINC codes
- 1988-5
- Tests that measure C-Reactive Protein, Quant
- Labcorp 7, Quest Diagnostics 3
See why clinicians order the test
Clinicians order the test when a person shows symptoms of a bacterial infection, such as fever, chills or rapid breathing.
Clinicians order the test to check for a chronic condition that causes inflammation.
Goal: Inflammation
Clinicians use the test to monitor for infection after surgery.
Clinicians use the test to monitor an infection or a chronic condition and how its treatment is going.
Clinicians use the test to help make treatment decisions for people with sepsis.
Read with companion markers
Choose the right version
C-Reactive Protein, CardiacHigh-sensitivity test
Clinicians use the hs-CRP version of the test to estimate a person's risk of heart disease.
Check what can shift results
Prepare for the test
Each statement links to the source we wrote it from. Last updated October 19, 2026.
Tests
Check the catalog code, specimen, method and preparation for every test that measures C-Reactive Protein, Quant. Select up to five tests to compare them side by side.
Labcorp 7 tests
Single-analyte tests
C-Reactive Protein (CRP), Quantitative 006627
Serum · Fasting not stated · Turnaround Within 1 day
Labcorp catalog pageMethod and collection
- Method
- Latex immunoturbidimetry
- Reference notes
- See table. Age Male (mg/L) Female (mg/L) 0 to 30 d Not established Not established 1 m to 17 y 0–7 0–9 >17 y 0–10 0–10
Panels that include this biomarker
Vectra® 504965
13 analytes · Serum · Fasting not stated · Turnaround 6 - 8 days
Labcorp catalog pageMethod and collection
- Method
- Multiplex bead-based immunoassay and Meso Scale Discovery Multi-array Platform
- Collection
- Allow specimen to clot for 30 minutes. Centrifuge and separate from cells within 45 minutes of draw. Transfer to a plastic transport tube before shipping.
Vectra® with CV Risk 504980
13 analytes · Serum · Fasting not stated · Turnaround 6 - 8 days
Labcorp catalog pageMethod and collection
- Method
- Multiplex bead-based immunoassay and Meso Scale Discovery Multi-array Platform
- Collection
- Allow specimen to clot for 30 minutes. Centrifuge and separate from cells within 45 minutes of draw. Transfer to a plastic transport tube before shipping.
COVID-19 Triage Profile 164052
20 analytes · Serum · Fasting not stated · Turnaround 1 - 2 days
Labcorp catalog pageMethod and collection
- Method
- See individual test components.
- Collection
- Blood should be collected in a blue-top tube containing 3.2% buffered sodium citrate. Evacuated collection tubes must be filled to completion to ensure a proper blood to anticoagulant ratio. The sample should be mixed immediately by gentle inversion at least six times to ensure adequate mixing of the anticoagulant with the blood. A discard tube is not required prior to collection of coagulation samples. When noncitrate tubes are collected for other tests, collect sterile and nonadditive (red-top) tubes prior to citrate (blue-top) tubes. Any tube containing an alternate anticoagulant should be collected after the blue-top tube. Gel-barrier tubes and serum tubes with clot initiators should also be collected after the citrate tubes. Centrifuge and carefully remove the plasma using a plastic transfer pipette, being careful not to disturb the cells.Transfer the plasma into a Labcorp PP transpak frozen purple tube with screw cap (Labcorp No. 49482). Freeze plasma within four hours of blood collection and maintain frozen until tested. To avoid delays in turnaround time when requesting multiple tests on frozen samples, please submit seperate frozen specimens for each test requested.
Chronic Urticaria (CU) Evaluation Profile 505805
24 analytes · Serum · Fasting not stated · Turnaround 7 - 10 days
Labcorp catalog pageMethod and collection
- Method
- See individual tests.
- Collection
- CBC+ESR: Invert lavender-top tube eight to 10 times immediately after tube is filled at the time of collection. Other tests: If a red-top tube is used, transfer separated serum to a plastic transport tube.
COVID-19 Severe Disease Progression Risk Profile 164049
25 analytes · Serum · Fasting not stated · Turnaround 2 - 4 days
Labcorp catalog pageMethod and collection
- Method
- See individual test components.
- Collection
- Blood should be collected in a blue-top tube containing 3.2% buffered sodium citrate. Evacuated collection tubes must be filled to completion to ensure a proper blood to anticoagulant ratio. The sample should be mixed immediately by gentle inversion at least six times to ensure adequate mixing of the anticoagulant with the blood. A discard tube is not required prior to collection of coagulation samples. When noncitrate tubes are collected for other tests, collect sterile and nonadditive (red-top) tubes prior to citrate (blue-top) tubes. Any tube containing an alternate anticoagulant should be collected after the blue-top tube. Gel-barrier tubes and serum tubes with clot initiators should also be collected after the citrate tubes. Centrifuge and carefully remove the plasma using a plastic transfer pipette, being careful not to disturb the cells.Transfer the plasma into a Labcorp PP transpak frozen purple tube with screw cap (Labcorp No 49482). Freeze plasma within four hours of blood collection and maintain frozen until tested. To avoid delays in turnaround time when requesting multiple tests on frozen samples, please submit seperate frozen specimens for each test requested.
Quest Diagnostics 3 tests
Single-analyte tests
C-Reactive Protein (CRP) 4420
Serum · Fasting not stated · Turnaround Set up: Mon-Fri; Report available: 5 days
Quest Diagnostics catalog pageMethod and collection
- Method
- Immunoturbidimetric
- Reference notes
- <8.0 mg/L
Panels that include this biomarker
Post COVID-19 Panel 11454
5 analytes · See individual tests · Fasting not stated
Quest Diagnostics catalog pageMethod and collection
- Method
- See individual tests
- Reference notes
- See individual tests
Post COVID-19 Expanded Panel 11453
7 analytes · See individual tests · Fasting not stated
Quest Diagnostics catalog pageMethod and collection
- Method
- See individual tests
- Reference notes
- See individual tests
0 of 5 tests selected
Pick one moreGoals and conditions
We link C-Reactive Protein, Quant to these goals and conditions from named guidelines and studies.
Energy and fatigueGoal, primary marker
NICE lists C-reactive protein among the tests to exclude other diagnoses when ME/CFS is suspected.
Sources
Check the guidelines, studies and lab catalogs behind every range and link on this page. Open a source to see each claim it backs.
Clinical guidelines
Myalgic encephalomyelitis (or encephalopathy)/chronic fatigue syndrome: diagnosis and management (NG206)
National Institute for Health and Care Excellence, 2021
Linked to Energy and fatigue (primary)
NICE lists C-reactive protein among the tests to exclude other diagnoses when ME/CFS is suspected.
Studies
Adjusting ferritin concentrations for inflammation: Biomarkers Reflecting Inflammation and Nutritional Determinants of Anemia (BRINDA) project
The American journal of clinical nutrition, 2017
Read together with
Studies adjust ferritin for inflammation using CRP, because unadjusted ferritin understates how common depleted iron stores are.
Lab catalogs
Labcorp test menu
Labcorp
Test catalog: 7 tests, with codes, specimens, methods and reference intervals
Quest Diagnostics test menu
Quest Diagnostics
Test catalog: 3 tests, with codes, specimens, methods and reference intervals
Reference sources
C-Reactive Protein (CRP) Test
MedlinePlus, National Library of Medicine
Before the test
MedlinePlus advises against stopping any prescription medicine without first talking with the provider.
“Don't stop taking any prescription medicines without talking with your provider first.”
Before the test
Before the test, MedlinePlus advises telling the provider about all supplements and medicines, including magnesium and NSAIDs such as ibuprofen and aspirin.
“So, tell your provider about any supplements or medicines that you take, including magnesium and non-steroidal anti-inflammatory drugs (NSAIDS) such as ibuprofen and aspirin.”
Reasons to test
Clinicians use the test to help make treatment decisions for people with sepsis.
“Make treatment decisions if you have sepsis.”
Reasons to test
Clinicians use the test to monitor an infection or a chronic condition and how its treatment is going.
“Monitor your condition and treatment if you have an infection or a chronic condition.”
Reasons to test
Clinicians use the test to monitor for infection after surgery.
“Monitor for infection after surgery.”
Reasons to test
Clinicians order the test to check for a chronic condition that causes inflammation.
“Check for a chronic condition that causes inflammation.”
Reasons to test
Clinicians order the test when a person shows symptoms of a bacterial infection, such as fever, chills or rapid breathing.
“You may need this test if you have symptoms of a bacterial infection, such as:”
Versions of the test
Clinicians use the hs-CRP version of the test to estimate a person's risk of heart disease.
“It is used to estimate your risk of heart disease.”
What can shift results
CRP levels are often slightly higher in females than in males.
“Females often have slightly higher CRP levels than males.”
What can shift results
Smoking and exposure to environmental toxins such as polluted air and hazardous waste can raise CRP levels.
“Smoking and exposure to environmental toxins such as polluted air and hazardous waste can also cause high CRP levels.”
What can shift results
Some medicines may affect the results of a CRP test.
“Some medicines may affect your results.”
What it reflects
CRP levels rise and fall with the amount of inflammation in the body.
“CRP levels rise and fall depending on how much inflammation is in your body.”
What it reflects
C-reactive protein is a protein the liver makes in response to inflammation in the body.
“Your liver makes CRP in response to inflammation.”
Versions of the test
The standard CRP test measures the same protein, but clinicians use it for different conditions than hs-CRP.
Retrieved October 19, 2026
C-Reactive Protein (CRP) Test
MedlinePlus, National Library of Medicine
The description at the top of this page
Codes and registries
LOINC 1988-5
Regenstrief Institute codes that identify the same result across labs.
Search ClinicalTrials.gov for C-Reactive Protein, Quant
Registered studies that measure C-Reactive Protein, Quant, on the U.S. National Library of Medicine registry.
Verify these ranges and sources
We compile this page from named laboratory catalogs, guidelines and studies. Labs calculate reference intervals from the people they test, for one assay method and one population group, so an interval describes that population rather than an optimal target.
Interpret your own results with a licensed clinician, or track your lab history and health goals in Aumnivida.
Spotted an error? Email hello@biomarkerlens.com with the page URL and the primary source that corrects the entry.