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C-reactive protein (CRP) concentration in 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 doctors assess inflammation, often used to monitor conditions like infections or autoimmune diseases."]

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

Key facts at a glance

LOINC
45070-0
Short code
C trach+GC rRNA Vag Ql Probe
Synonyms
C trach+GC rRNA Vag Ql Probe
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
probe
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?

Your healthcare provider may order this test to check for signs of inflammation, monitor chronic conditions (such as rheumatoid arthritis or heart disease), or evaluate responses to treatments. It can also help diagnose infections or other inflammatory conditions.

What to Expect Before the Test

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

What the Results Mean

Higher-than-normal CRP levels may indicate inflammation, infections, or other health issues. Lower levels suggest reduced inflammation. Your results will be discussed with you by your healthcare provider.

Common Conditions Monitored

This test is often used to monitor conditions like heart disease, infections, autoimmune disorders (such as lupus or rheumatoid arthritis), or to check how well treatments are working.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: CRP is a marker of systemic inflammation. Elevated levels can signal infections, autoimmune activity, or other inflammatory processes. It’s not specific to one condition but helps guide treatment decisions and disease management.

Short name

CRP (Plasma)

Frequently asked questions

What causes CRP levels to change?
CRP levels can rise due to infections (like a cold or urinary tract infection), injuries, autoimmune diseases, or certain medications. They may also drop if inflammation decreases, such as after treatment for an infection or disease.
How long does it take to get results?
Results are typically available within 1 to 3 business days, depending on your lab’s processing time. Your provider will discuss them with you during your follow-up visit.
Can diet or exercise affect CRP levels?
Yes, lifestyle factors like diet (e.g., Mediterranean diet), exercise, and weight management may influence CRP levels. Reducing inflammation through healthy habits can sometimes lower CRP, but results vary by individual.
  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