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C-reactive protein (CRP) concentration, plasma

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

This test measures the level of C-reactive protein, a protein produced by the liver in response to inflammation in the body.

Quick summary

["CRP helps identify inflammation, often used to monitor conditions like infections or autoimmune diseases."]

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

Key facts at a glance

LOINC
80625-7
Short code
ZIKV NAb sp2 Titr CSF Nt
Synonyms
ZIKV NAb sp2 Titr CSF Nt
Category
chemistry
Sample
csf
Container
Sterile tube
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
neut
Specimen volume
1-2 mL
Stability
Immediate analysis required, Refrigerated: 1h
Hemolysis max
200
TAT
4–24 hours
Order
routine

Why Is This Test Done?

Your doctor may order a CRP test to check for signs of inflammation, monitor chronic conditions like arthritis or heart disease, or evaluate responses to treatments. It can also help diagnose infections or assess risks for certain health issues.

What Does a High or Low CRP Level Mean?

Elevated CRP levels often indicate inflammation or infection. Very high levels may signal severe conditions like sepsis or severe infections. Very low levels might suggest no active inflammation, but they can also be due to certain medications or medical conditions.

How Is This Test Performed?

A blood sample is taken from a vein, usually in your arm. The blood is then sent to a lab where it is processed to measure CRP levels using a sensitive immunoassay method.

What Are Common Results and Next Steps?

Results are typically reported in milligrams per liter (mg/L). If your CRP level is higher than expected, your doctor may recommend further tests or treatments to address the underlying cause. If it’s low, they may check for other reasons, such as medications or underlying conditions.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: CRP plays a key role in detecting and monitoring inflammation across many diseases. It’s a useful marker for conditions like rheumatoid arthritis, cardiovascular disease, and infections. CRP levels can also help guide decisions about treatments and follow-up care.

Short name

CRP (Plasma)

Frequently asked questions

What causes CRP levels to change?
CRP levels rise in response to inflammation caused by infections, injuries, autoimmune diseases, or other conditions that trigger the body’s immune response. Certain medications, such as steroids, can also lower CRP levels.
How soon will I get my results?
Results are usually available within a few days to a week, depending on your lab’s processing time. Your doctor will contact you with the results and any needed next steps.
Can I do anything to prepare for this test?
No special preparation is usually needed, but avoid strenuous exercise 24 hours before the test if your doctor advises it. If you’re on blood thinners, inform your healthcare provider before the test.
  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