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C-reactive protein (CRP) by immunoassay (qualitative probe)

Published: August 9, 2026Updated: August 16, 2026

This test measures whether your blood has a protein called C-reactive protein (CRP), which can indicate inflammation in your body.

Quick summary

["CRP helps doctors check for signs of inflammation that may be causing symptoms or underlying conditions."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
64017-7
Short code
C trach+GC pnl Spec NAA+probe
Synonyms
C trach+GC pnl Spec NAA+probe
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
probe-amp-tar
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

What CRP Measures

CRP is a protein produced by your liver in response to inflammation. It rises when your body is fighting infection, healing from injury, or dealing with conditions like arthritis, autoimmune diseases, or other inflammatory processes.

Why It’s Done

Your healthcare provider may order this test to monitor inflammation, assess risk for conditions like heart disease, or evaluate symptoms such as fever, joint pain, or unexplained swelling.

How It’s Performed

A small blood sample is drawn from a vein in your arm. The sample is tested using a specific immunoassay probe to detect CRP levels qualitatively (yes/no presence). Results are not quantified numerically.

What to Expect Before or After

No special preparation is needed. You may feel slight discomfort at the injection site, but it usually resolves quickly. If you have a bleeding disorder or take blood thinners, let your provider know before the test.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Elevated CRP levels suggest inflammation, which can signal infections, injuries, or inflammatory diseases. While CRP alone doesn’t diagnose a specific condition, it often guides further testing or treatment decisions. Chronic, high CRP may raise concerns for conditions like cardiovascular disease or certain cancers.

Short name

CRP Qualitative Probe

Frequently asked questions

What does a positive CRP result mean?
A positive CRP result means your blood contains detectable CRP protein, indicating inflammation is present. This doesn’t specify the cause but signals your body is responding to an inflammatory process.
Can CRP levels change over time?
Yes, CRP levels can fluctuate based on your health status, recent infections, medications, or other factors. Your provider may retest CRP levels to track changes over time.
Is CRP the same as a complete blood count (CBC)?
No, CRP is a specific protein test for inflammation. A CBC checks for red/white blood cells and platelets, while CRP focuses on inflammation markers.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy