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C-reactive protein (CRP) concentration in serum/plasma

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

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

Quick summary

["CRP helps doctors assess inflammation in your body."]

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

Key facts at a glance

LOINC
16597-7
Short code
C trach B IgG Ser-aCnc
Synonyms
C trach B IgG Ser-aCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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 a CRP test to check for signs of inflammation, monitor chronic conditions like arthritis or heart disease, or evaluate infections. It can also help determine if you have an immune response after surgery or treatment.

What Does a High CRP Level Mean?

Elevated CRP levels often indicate inflammation, which can be caused by infections, injuries, autoimmune diseases, or other health issues. However, CRP alone doesn’t diagnose a specific condition—it’s usually used alongside other tests and symptoms.

What Does a Low CRP Level Mean?

Low CRP levels typically suggest reduced inflammation, which may be normal if you’re healthy or if inflammation is mild. Very low levels could also indicate certain immune system conditions or medications that suppress inflammation.

How Is This Test Performed?

A small blood sample is taken from a vein in your arm. The blood is sent to a lab, where it’s analyzed to measure CRP levels using a sensitive detection method.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

CRP

Frequently asked questions

How often should I expect this test?
The frequency depends on your medical condition and healthcare provider’s instructions. Some people get CRP tests every few months, while others may need them less often or only when symptoms change.
Does diet or exercise affect CRP levels?
Yes! Certain foods, like omega-3 fatty acids (found in fish), anti-inflammatory herbs, and a balanced diet, may help lower CRP levels. Regular physical activity can also reduce inflammation. Avoiding smoking and managing stress are also important.
Can CRP levels be affected by medications?
Some medications, such as corticosteroids (e.g., prednisone) or nonsteroidal anti-inflammatory drugs (NSAIDs), can lower CRP levels. Always discuss any medications with your provider before interpreting results.
  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