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C-reactive protein (CRP) – Serum or Plasma Concentration

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 doctors assess inflammation, which can be linked to infections, injuries, or other health conditions."]

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

Key facts at a glance

LOINC
86141-9
Short code
S pneum Da 7A IgG Ser-aCnc
Synonyms
S pneum Da 7A IgG Ser-aCnc
Category
coagulation
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 healthcare provider may order a CRP test to monitor conditions like arthritis, heart disease, infections, or to check for signs of inflammation after surgery or injury. It can also help track how well treatments are working for certain inflammatory diseases.

What to Expect Before the Test

No special preparation is usually needed. You may have a small needle inserted into your arm or vein to draw blood. If you’re on blood thinners, let your provider know before the test.

What the Results Mean

CRP levels vary depending on health status. Higher than normal levels often indicate inflammation, but results alone don’t diagnose a specific condition. Your provider will interpret results in the context of your symptoms and medical history.

Possible Causes of Abnormal Results

Elevated CRP levels can be caused by infections (like pneumonia or urinary tract infections), autoimmune diseases (like lupus or rheumatoid arthritis), heart disease, or other inflammatory conditions. Low levels may suggest no active inflammation, but can also occur with certain chronic illnesses.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

CRP (Serum/Plasma)

Frequently asked questions

What does a CRP test tell me about my health?
A CRP test helps identify inflammation in your body, which can signal infections, autoimmune diseases, or other health issues. It’s often used as a screening tool or to monitor treatment progress for conditions like arthritis or heart disease. However, CRP alone doesn’t pinpoint the exact cause of inflammation.
Can I lower my CRP levels naturally?
Yes, lifestyle changes like regular exercise, a balanced diet (rich in anti-inflammatory foods like fish, vegetables, and whole grains), managing stress, and avoiding smoking can help reduce inflammation and potentially lower CRP levels over time. Always discuss these changes with your healthcare provider.
How often should I get a CRP test?
Your provider will determine how often you need a CRP test based on your medical history, symptoms, and treatment plan. Some people get it yearly or more frequently if they have chronic conditions like arthritis or heart disease. Follow your provider’s recommendations.
  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