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C-reactive protein (CRP) by nephelometry

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 your body.

Quick summary

["CRP helps doctors identify and monitor inflammation, often used to check for infections or other health issues."]

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

Key facts at a glance

LOINC
92973-7
Short code
K oxytoca DNA BAL NAA+non-prb-NCncRng
Synonyms
K oxytoca DNA BAL NAA+non-prb-NCncRng
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
non-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

Why Is This Test Done?

Your healthcare provider may order a CRP test to check for signs of inflammation, monitor chronic conditions like arthritis, or evaluate symptoms such as fever, pain, or swelling that might indicate an infection or other health problem. It can also be used before and after treatments to see how your body responds.

What to Expect Before the Test

No special preparation is usually needed for this test. You may have a small needle inserted into your arm to draw blood, which is then sent to a lab for analysis. If you’re taking blood from your own home, follow your healthcare provider’s instructions carefully.

What the Results Mean

CRP levels can vary widely depending on your health status. Higher levels often suggest inflammation, infections, or other medical conditions. Your results will be discussed with you by your healthcare provider, who will consider them alongside your overall health and symptoms.

Common Conditions Monitored

CRP is commonly used to monitor conditions like rheumatoid arthritis, lupus, heart disease, and infections such as pneumonia or sepsis. It can also help track how well treatments are working.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: CRP is a marker for inflammation and is often used as a screening or monitoring tool. While it doesn’t diagnose specific conditions, elevated levels may prompt further testing or adjustments to treatment plans.

Short name

CRP (Nephelometry)

Frequently asked questions

How often will I need this test?
The frequency depends on your medical needs. Some people get CRP tests yearly or more often if they have chronic conditions like arthritis or heart disease. Your doctor will let you know how often you need it based on your situation.
What does a high CRP level mean?
A high CRP level often means your body is fighting inflammation or infection. It could indicate conditions like an infection, autoimmune disease, or other inflammatory disorders. Your doctor will review your results with you to understand what it means for your health.
Can I eat or drink before this test?
You can eat and drink normally before this test unless your doctor advises otherwise. Blood tests like CRP don’t require fasting, so there’s no need to change your diet beforehand.
  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