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C-reactive protein (CRP) by turbidimetry (serum/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, autoimmune diseases, or after surgery."]

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

Key facts at a glance

LOINC
94831-5
Short code
VZV DNA Amn NAA+probe-aCnc
Synonyms
VZV DNA Amn NAA+probe-aCnc
Category
chemistry
Sample
fluid
Container
Sterile tube
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
probe-amp-tar
Specimen volume
2-5 mL
Stability
Room temperature: 2h, Refrigerated: 24h
Hemolysis max
300
TAT
4–24 hours
Order
routine

Why Is CRP Tested?

Doctors may order a CRP test to check for signs of inflammation, track how well a treatment is working, or evaluate conditions like infections, heart disease, or certain types of arthritis. It can also help monitor recovery after surgery or illness.

What Does CRP Tell You?

Higher CRP levels often indicate inflammation, which can be caused by infections, injuries, or autoimmune diseases. While CRP doesn’t specify the cause, it helps guide further testing or treatment decisions.

How Is the Test Performed?

A blood sample is drawn from a vein, usually in your arm. The blood is processed to separate serum or plasma, which is then analyzed to measure CRP levels using a turbidimetric method.

What Are Common Uses?

CRP is commonly used to monitor chronic conditions like rheumatoid arthritis, to assess cardiovascular risk, or to evaluate responses to treatments for inflammation.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

CRP plays a key role in identifying and managing inflammatory processes. While it doesn’t diagnose a specific condition, elevated levels may prompt additional testing or adjustments in treatment plans, such as for infections, autoimmune disorders, or post-surgical monitoring.

Short name

CRP

Frequently asked questions

What does a high CRP level mean?
A high CRP level suggests inflammation is present in your body. This could be due to infections, injuries, autoimmune diseases, or other conditions that trigger an immune response. Your doctor will use these results along with other tests and symptoms to determine the cause.
What does a low CRP level mean?
A low CRP level generally means there is less inflammation in your body. However, it doesn’t rule out all causes of inflammation, so your doctor may still recommend further evaluation if needed.
Can CRP levels change over time?
Yes, CRP levels can fluctuate depending on your health status, recent infections, medications, or other factors. Regular monitoring can help track changes in inflammation, especially in chronic conditions.
  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