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C-reactive protein (CRP) quantitative measurement

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

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

Quick summary

["CRP helps doctors assess inflammation, infection risk, or response to treatment."]

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

Key facts at a glance

LOINC
22174-7
Short code
C pneum IgM Titr Ser
Synonyms
C pneum IgM Titr Ser
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 This Test Is Done

Your doctor may order a CRP test to monitor conditions like arthritis, heart disease, or infections, or to check if your body is responding to treatment for inflammation or illness. It can also help evaluate risk for certain health issues before symptoms appear.

What to Expect During the Test

A small blood sample is taken from a vein in your arm. You may feel a slight pinch, but it usually doesn’t cause pain. The test is quick and done in a lab.

What the Results Mean

Higher CRP levels often indicate inflammation, infection, or other health problems. Your doctor will interpret the results in relation to your medical history and other tests.

Common Conditions Monitored

CRP is used to track conditions like rheumatoid arthritis, heart disease, or infections. It can also help guide decisions about medications or treatments.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

C-reactive protein is a marker of inflammation. Elevated levels may signal infections, autoimmune diseases, or other inflammatory conditions. It can also be used to assess cardiovascular risk or monitor treatment effectiveness in certain conditions.

Short name

CRP Level

Frequently asked questions

What causes CRP levels to be high?
High CRP levels can be caused by infections (like pneumonia or urinary tract infections), injuries, autoimmune diseases (like lupus or rheumatoid arthritis), or other inflammatory conditions. Stress, certain medications, or obesity may also influence CRP levels.
How often should I get this test?
Your doctor will determine how often you need this test based on your health needs. Some people get it yearly for general health checks, while others may need it more frequently if they have ongoing conditions.
Can diet or lifestyle changes affect CRP levels?
Yes, diet, exercise, and weight management can influence CRP levels. Eating a heart-healthy diet, staying active, and maintaining a healthy weight may help lower CRP and reduce 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