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

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

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

Quick summary

["CRP helps identify and monitor inflammation, often used to check for infections, autoimmune conditions, or other inflammatory diseases."]

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

Key facts at a glance

LOINC
107052-3
Short code
CLL MRD Mar FC
Synonyms
CLL MRD Mar FC
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
flow-cytometry
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 Is This Test Done?

Your healthcare provider may order CRP testing to evaluate signs of inflammation, monitor chronic conditions like rheumatoid arthritis or lupus, or assess for infections such as pneumonia or sepsis. It can also be used before surgery or during pregnancy to check for risks of complications.

What Does a High CRP Level Mean?

Elevated CRP levels often indicate an active inflammatory process, such as an infection, injury, or autoimmune disease. However, it can also be raised due to other factors like obesity, smoking, or certain medications.

What Does a Low CRP Level Mean?

Low CRP levels typically suggest minimal inflammation. However, very low levels might not always indicate no inflammation, especially in chronic conditions where levels can fluctuate.

Common Conditions Monitored with CRP

CRP is commonly used to monitor conditions like cardiovascular disease, inflammatory bowel disease, and certain infections. It can also help guide treatment decisions for conditions like rheumatoid arthritis or lupus.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

CRP plays a key role in assessing and managing inflammation-related health issues. It is often used as a marker to track disease activity, response to treatment, or risk of complications. While CRP is not diagnostic on its own, it provides important information to support overall clinical decisions.

Short name

CRP

Frequently asked questions

What triggers CRP levels to rise?
CRP levels can rise due to infections (like bacterial or viral illnesses), injuries, surgeries, or certain medical conditions such as autoimmune diseases. Stress, smoking, and obesity may also contribute to higher CRP levels.
How often should I get CRP tested?
The frequency of CRP testing depends on your medical condition and healthcare provider’s recommendations. Some people may need CRP tests regularly, while others may only need them occasionally, such as before or after treatment for an illness.
Can CRP levels be affected by diet or lifestyle?
Yes, lifestyle factors like diet, exercise, smoking, and weight can influence CRP levels. Reducing inflammation through healthy eating, regular physical activity, and avoiding smoking may help lower CRP levels over time.
  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