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C-reactive protein, serum/plasma mass concentration

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 in your body."]

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

Key facts at a glance

LOINC
42219-6
Short code
Cr Ur-sCnc
Synonyms
Cr Ur-sCnc
Category
chemistry
Sample
urine
Container
Sterile urine container
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
10 mL
Stability
Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
0
Lipemia max
0
Icterus max
0
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 conditions like infections, autoimmune diseases, or heart disease, or evaluate responses to treatments. It can also help identify risks for conditions like heart attacks or certain cancers.

What to Expect Before the Test

No special preparation is needed for this blood test. You may have a small needle inserted into a vein, usually in your arm, to draw a blood sample. The process is quick and usually causes only minor discomfort.

What the Results Mean

Higher than normal CRP levels may indicate inflammation, infections, or other health issues. Lower levels suggest reduced inflammation. Your healthcare provider will interpret your results in the context of your overall health and medical history.

Common Conditions Monitored

CRP is often used to monitor conditions such as rheumatoid arthritis, lupus, heart disease, infections, and inflammatory bowel disease. It can also be part of routine check-ups for those at higher risk for heart disease.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

CRP

Frequently asked questions

What causes CRP levels to be high?
CRP levels can rise due to infections (like colds or flu), injuries, surgeries, certain medications, or underlying health conditions such as autoimmune diseases. Stress, smoking, and obesity may also influence CRP levels.
How often should I get this test?
The frequency depends on your medical condition and healthcare provider’s recommendations. Some people get CRP tests yearly or more often if they have ongoing health concerns or conditions requiring monitoring.
Can diet or lifestyle changes affect CRP levels?
Yes, diet, exercise, and weight management can influence CRP levels. Reducing inflammation through a healthy diet, regular physical activity, and avoiding smoking can help lower CRP levels.
  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