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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 your liver in response to inflammation or infection in your body.

Quick summary

["CRP helps doctors track inflammation, infection, or risk of future health issues like heart disease."]

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

Key facts at a glance

LOINC
57288-3
Short code
C trach rRNA Nph Ql NAA+probe
Synonyms
C trach rRNA Nph Ql NAA+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-amp-tar
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 Might Be Ordered

Your healthcare provider may order this test to check for signs of inflammation, monitor conditions like rheumatoid arthritis or lupus, evaluate infection, or assess risk for heart disease or other chronic illnesses. It can also be used to monitor treatment effectiveness for certain conditions.

What to Expect Before the Test

No special preparation is usually needed. You may be asked to fast for 8–12 hours before the test if it’s part of a broader blood panel. Bring any medications you’re taking to your appointment.

How the Test Works

A small sample of your blood is drawn from a vein, typically in your arm. The sample is sent to a lab where it’s analyzed to measure CRP levels using a sensitive detection method.

What the Results Mean

Higher CRP levels often indicate inflammation, but they can also be influenced by factors like recent illness, stress, or certain medications. Your results will be compared to a baseline or clinical context provided by your healthcare provider.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

CRP (Plasma)

Frequently asked questions

How often should I get this test?
Your doctor will determine how often you need this test based on your health status, symptoms, and treatment plan. Some people get it yearly for heart health monitoring, while others may need it more frequently if they have an ongoing condition.
Can diet or exercise affect CRP levels?
Yes, lifestyle factors like diet (e.g., Mediterranean diet), exercise, and weight management can influence CRP levels. Reducing inflammation through healthy habits may lower CRP, but results can vary by individual.
What if my CRP is high?
A high CRP level may signal inflammation that needs further investigation. Your doctor could recommend additional tests (like bloodwork or imaging) or suggest lifestyle changes to address underlying causes, such as infections, autoimmune conditions, or heart disease risk factors.
  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