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C-reactive protein (CRP) by nephelometry (serum/plasma)

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

This test measures a protein produced by the liver in response to inflammation, helping detect or monitor low-level inflammation in your body.

Quick summary

["High sensitivity CRP helps track subtle inflammatory activity often missed by standard CRP tests."]

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

Key facts at a glance

LOINC
69240-0
Short code
Deprecated RF Abd PC bx
Synonyms
Deprecated RF Abd PC bx
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
rf
CPT
86430
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

Why It’s Done

Your doctor may order this test to check for early signs of inflammation, especially in conditions like cardiovascular disease, autoimmune disorders, or after surgery. It’s also used to monitor treatment progress in chronic inflammatory conditions.

What to Expect

A small blood sample is drawn from a vein, usually in your arm. The blood is sent to a lab where it’s analyzed using a nephelometry method to measure CRP levels precisely.

This test is often used in routine cardiovascular risk assessments, monitoring for infections, or evaluating response to anti-inflammatory treatments.

While CRP is a marker of inflammation, it doesn’t diagnose specific conditions. Results are interpreted alongside other symptoms and tests by your healthcare provider.

What Your Results Mean

Elevated levels may indicate inflammation, infection, or other health issues. Very low levels might suggest no active inflammation. Your doctor will discuss results in the context of your overall health.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: CRP is a key biomarker for assessing systemic inflammation. High-sensitivity CRP is particularly useful for detecting mild to moderate inflammation, which can be critical in early disease detection (e.g., atherosclerosis) or post-treatment monitoring. It’s not diagnostic but provides critical context for guiding care decisions.

Short name

CRP (High Sensitivity)

Frequently asked questions

What causes CRP levels to change?
CRP rises in response to infections, injuries, surgeries, or autoimmune conditions. Stress, certain medications, or chronic illnesses like arthritis can also affect levels. Smoking, obesity, or poor diet may influence baseline CRP.
How often should I get this test?
Frequency depends on your health condition. Your doctor may recommend periodic testing for cardiovascular risk assessment, chronic inflammation monitoring, or after a recent illness. Follow their guidance.
Can lifestyle changes affect CRP levels?
Yes! Regular exercise, a balanced diet, quitting smoking, and managing stress can lower CRP levels. Weight loss and controlling conditions like diabetes or hypertension may also help reduce inflammation.
  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