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C-reactive protein (serum/plasma 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
89640-7
Short code
C pneum IgM Ser Ql IA
Synonyms
C pneum IgM Ser Ql IA
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ia
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?

Doctors 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 be used as a screening tool in certain situations, such as before surgery or during pregnancy.

What to Expect Before the Test

No special preparation is usually needed. You may be asked to fast for a few hours before the test if it’s part of a larger blood workup, but this isn’t always required for CRP alone. Wear comfortable clothing and plan to stay near the testing site for a short time.

What Happens During the Test?

A healthcare professional will draw blood from a vein, typically in your arm. You may feel a slight pinch or discomfort, but it usually lasts only a few seconds. The blood sample is then sent to a lab for analysis.

What Are the Results?

Results are typically reported in milligrams per liter (mg/L). Higher than normal levels may indicate inflammation, infection, or other health issues. Your doctor will interpret the results in the context of your overall health and medical history.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

CRP (Serum)

Frequently asked questions

How often should I get this test?
The frequency depends on your health condition and why the test was ordered. Your doctor will determine the best schedule based on your needs, such as monitoring chronic inflammation or evaluating treatment progress.
Can diet or lifestyle affect CRP levels?
Yes, diet and lifestyle can influence CRP levels. High-fat or processed foods, smoking, and physical inactivity may raise inflammation. Eating a balanced diet rich in fruits, vegetables, and omega-3 fatty acids, along with regular exercise, may help lower CRP levels over time.
What if my CRP test is elevated?
If your CRP test is elevated, your doctor may recommend further testing or adjustments to your treatment plan. This could include additional blood tests, imaging, or lifestyle changes to address the underlying cause of inflammation.
  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