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C-reactive protein (CRP) mass concentration in serum/plasma

Published: August 9, 2026Updated: August 17, 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 identify and monitor inflammation, often used to check for infections or other inflammatory conditions."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
2151-9
Short code
CK CSF-cCnc
Synonyms
CK CSF-cCnc
Category
chemistry
Sample
csf
Container
Sterile tube
Units
N/A
Ref low
22
Ref high
198
Critical range
— – 10000 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
82553
Specimen volume
1-2 mL
Stability
Immediate analysis required, Refrigerated: 1h
Hemolysis max
200
TAT
4–24 hours
Order
routine

Why Is This Test Done?

Your healthcare provider may order a CRP test to check for signs of inflammation, monitor chronic conditions like arthritis or heart disease, or evaluate infections. It can also help assess how your body is responding to treatment for certain conditions.

What to Expect Before the Test

No special preparation is usually needed. You may be asked to fast before the test, but this is often not required for CRP. Bring any medications you’re currently taking to your appointment.

How the Test Is Done

A small needle is inserted into your arm to draw blood. You may feel a slight pinch, but the procedure is quick and usually painless. The blood sample is sent to a lab for analysis.

What the Results Mean

Results are not always given in numbers, as reference ranges can vary by lab. Higher than normal levels may suggest inflammation, infection, or other health issues. Your doctor will interpret the results in the context of your medical history and symptoms.

Reference range

Adult males: 22-198 U/L; Females: 22-198 U/LN/A

Specimen: csf

No special preparation required. Inform provider of any chest pain or symptoms.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

CRP

Frequently asked questions

What causes CRP levels to be higher than usual?
Infections (such as pneumonia or urinary tract infections), injuries, surgeries, autoimmune diseases (like lupus or rheumatoid arthritis), or certain medications can raise CRP levels. Stress or recent illness may also temporarily increase it.
How long does it take to get results?
Results are typically available within 24 to 48 hours, depending on your lab’s processing time. Your doctor will contact you once they have the results.
Can lifestyle changes affect CRP levels?
Yes, lifestyle factors like diet, exercise, smoking, and stress can influence CRP levels. Reducing inflammation through healthy habits—such as eating a balanced diet, staying active, and avoiding smoking—may help lower CRP levels over time.
  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 17, 2026. · Read our editorial policy