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C-reactive protein (CRP) mass concentration in serum/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 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
2434-9
Short code
HVA CSF-mCnc
Synonyms
HVA CSF-mCnc
Category
chemistry
Sample
csf
Container
Sterile tube
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
1-2 mL
Stability
Immediate analysis required, Refrigerated: 1h
Hemolysis max
200
TAT
4–24 hours
Order
routine

Why CRP Matters in Your Health

CRP is a marker that signals your body’s immune response. It rises when tissues are damaged or when infections or inflammatory conditions (such as arthritis or heart disease) are present. While CRP alone doesn’t diagnose a specific condition, it can guide treatment decisions by showing whether inflammation is active.

Common Uses of CRP Testing

Doctors may order CRP tests to monitor chronic conditions like rheumatoid arthritis, to check for signs of infection (e.g., pneumonia, sepsis), or to evaluate heart health before or after procedures. It’s also used in research to track inflammation over time.

How the Test Works

Your blood sample is drawn and analyzed using a sensitive method to detect CRP levels. The test measures the mass concentration of CRP, which helps determine how much protein is present in your bloodstream.

What to Expect Before or After the Test

No special preparation is needed, but you may be asked to fast for 8–12 hours if your doctor specifies it. After the test, you’ll likely have a small bruise or sore spot where the needle was inserted. Rest and drink fluids as usual.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

CRP

Frequently asked questions

CRP levels can vary widely depending on your health status. High CRP levels may indicate inflammation, but they don’t always point to a specific cause. Doctors use CRP alongside other tests and symptoms to make a diagnosis and adjust treatment plans accordingly.
CRP tests are often used to monitor chronic conditions like arthritis or heart disease, but they’re not definitive on their own. If your levels are elevated, your doctor may recommend further testing to identify the root cause.
How often should I get a CRP test?
The frequency depends on your medical condition. For example, people with chronic inflammatory diseases may get CRP tests every few months, while healthy individuals may only need it if they have symptoms of infection or illness.
What does a high CRP level mean?
A high CRP level suggests inflammation is present, but it doesn’t always mean you have an infection or disease. Your doctor will consider your symptoms, medical history, and other test results to determine the next steps.
  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