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Serum or plasma mass concentration of C-reactive protein

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

This test measures the amount of C-reactive protein in your blood, a substance produced by your liver that rises in response to inflammation or infection.

Quick summary

["CRP helps doctors assess inflammation, track infections, or monitor conditions like arthritis or heart disease."]

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

Key facts at a glance

LOINC
58862-4
Short code
GH sp46 SerPl-mCnc
Synonyms
GH sp46 SerPl-mCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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 CRP Matters in Your Health

CRP is a marker for inflammation, meaning it signals when your body is responding to injury, infection, or autoimmune activity. While not specific to any single condition, elevated levels can indicate widespread inflammation that may require further evaluation.

When This Test Is Ordered

Doctors may order CRP tests to monitor chronic conditions (e.g., rheumatoid arthritis, inflammatory bowel disease), evaluate suspected infections, or assess post-surgery or post-injury healing. It’s also used in screening for cardiovascular risks or to guide treatment decisions.

How the Test Works

Your blood sample is drawn and analyzed to detect CRP levels. The test measures mass concentration, meaning it quantifies the protein’s weight per volume of blood, though exact reference ranges vary by lab and clinical context.

What to Expect Before the Test

No special preparation is needed, but inform your doctor about recent illnesses, medications (especially steroids), or conditions like infections or autoimmune diseases, as these can affect results.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

C-reactive protein (CRP) mass concentration

Frequently asked questions

How high or low are my CRP levels?
CRP levels alone don’t diagnose conditions—they’re part of a broader picture. Mild elevations (up to 10 mg/L) may signal low-grade inflammation, while very high levels (above 100 mg/L) could indicate severe infection or sepsis. Your doctor will interpret results in context of your symptoms and other tests.
Can CRP levels change with diet or exercise?
Dietary factors like omega-3 fatty acids or anti-inflammatory foods may influence CRP, but the effect is modest. Regular physical activity can lower CRP slightly, but results depend on overall health and underlying conditions.
Does this test replace other blood tests?
No, CRP is one tool among many. It complements tests like white blood cell counts or erythrocyte sedimentation rates (ESR) to pinpoint inflammation sources. Your doctor will use CRP alongside clinical judgment and other data to guide care.
  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