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

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 identify inflammation, guiding treatment decisions."]

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

Key facts at a glance

LOINC
31294-2
Short code
C trach B IgA Ser-aCnc
Synonyms
C trach B IgA 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 CRP Matters in Your Health

CRP is a marker that signals your body’s immune response to inflammation. High levels may indicate infections, autoimmune conditions, or other inflammatory processes. It’s often used alongside other tests to assess overall health or monitor conditions like heart disease or arthritis.

Common Uses for CRP Testing

Doctors may order CRP tests to check for infections (e.g., pneumonia, urinary tract infections), evaluate heart disease risk, monitor autoimmune diseases (like rheumatoid arthritis), or assess response to treatment for conditions causing chronic inflammation.

What to Expect Before or After the Test

No special preparation is needed for this blood test. You may have a small needle inserted into your arm to draw a blood sample. The process is quick and usually painless. Results are typically ready within a few days.

Possible Results and Next Steps

Results are interpreted by your healthcare provider based on your overall health. Elevated CRP may prompt further testing or adjustments to treatment, while normal levels don’t guarantee no inflammation is present. Follow-up may include additional blood tests or consultations with your doctor.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

CRP

Frequently asked questions

How long does it take to get CRP test results?
Results are usually available within 24 to 48 hours, depending on your lab’s processing time. Your doctor will discuss the findings with you during your follow-up visit.
Can CRP levels change with diet or exercise?
Yes, lifestyle factors like diet, exercise, and stress can influence CRP levels. Reducing inflammation through healthy habits may lower CRP, but results depend on the underlying cause of your test.
Is CRP the same as a complete blood count (CBC)?
No, CRP is a specific protein marker for inflammation, while a CBC checks for red and white blood cell counts, platelets, and red blood cell health. Both tests serve different diagnostic purposes.
  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