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C-reactive protein (serum) concentration by nephelometry

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

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

Quick summary

["CRP helps doctors assess inflammation and identify possible infections or other health issues."]

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

Key facts at a glance

LOINC
6912-0
Short code
C pneum IgA Titr Ser IF
Synonyms
C pneum IgA Titr Ser IF
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
if
CPT
82784
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 this test to check for signs of inflammation, monitor conditions like arthritis, infections, or autoimmune diseases, or evaluate responses to treatments. It can also be used to screen for certain risks, such as heart disease.

What to Expect Before the Test

No special preparation is needed. You may have a small needle inserted into your arm to draw blood. If you’re on blood thinners, let your provider know before the test.

What the Results Mean

Higher than expected levels may indicate inflammation, infections, or other health problems. Lower levels might suggest reduced inflammation, but results depend on your overall health and medical history.

Common Conditions Monitored

This test is often used to monitor conditions like rheumatoid arthritis, infections (e.g., pneumonia), heart disease, or to check how well treatments are working.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

CRP (Serum)

Frequently asked questions

What causes CRP levels to rise?
CRP levels can increase due to infections (like flu or urinary tract infections), injuries, surgeries, or certain medical conditions such as rheumatoid arthritis or heart disease. Stress or certain medications may also affect results.
How long does it take to get results?
Results are typically available within 24 to 48 hours, depending on your lab’s processing time. Your provider will discuss the meaning of your results with you.
Can diet or exercise affect CRP levels?
Yes, lifestyle factors like diet, exercise, and smoking can influence CRP levels. Eating a balanced diet, staying active, and avoiding smoking may help lower inflammation 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