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C-reactive protein (CRP) mass 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 or infection in your body.

Quick summary

["CRP helps your doctor assess 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
48265-3
Short code
Storage Mite Mix LR-mCnc
Synonyms
Storage Mite Mix LR-mCnc
Category
glucose
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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 doctor may order this test to check for signs of inflammation, infection, or other conditions like autoimmune diseases, heart disease, or kidney problems. It can also help monitor treatment progress for certain conditions.

What Does a High or Low Level Mean?

Elevated CRP levels often indicate inflammation or infection. Very high levels may suggest severe conditions like infections, autoimmune disorders, or heart disease. Very low levels might suggest no active inflammation, but this can also be normal depending on your health status.

How Is the Test Performed?

A blood sample is taken from a vein, usually in your arm. The blood is then sent to a lab where it is processed to separate plasma, and the CRP level is measured using a sensitive detection method.

What Should You Do Before the Test?

Avoid strenuous exercise or significant physical activity 24 hours before the test. If you have an infection, fever, or recent illness, inform your doctor, as these can affect results.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

CRP Plasma

Frequently asked questions

How long does it take to get my CRP test results?
Results are typically available within 1 to 3 business days, depending on your lab’s processing schedule.
Can I eat or drink before this test?
You can eat and drink normally before this test unless instructed otherwise by your healthcare provider.
Does this test require fasting?
No fasting is required for this test.
  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