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

Published: August 9, 2026Updated: August 16, 2026

This test measures the level of C-reactive protein (CRP) in your blood, a protein produced by your liver in response to inflammation.

Quick summary

["CRP helps identify inflammation, often used to monitor conditions like infections, autoimmune diseases, or post-surgery recovery."]

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

Key facts at a glance

LOINC
14461-8
Short code
C trach Bld Ql Cult
Synonyms
C trach Bld Ql Cult
Category
chemistry
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
organism-specific-culture
Specimen volume
3 mL
Stability
Room temperature: 4h, Refrigerated: 24h
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

Why This Test Is Done

Doctors may order a CRP test to check for signs of inflammation in your body. It can help diagnose conditions such as infections (like pneumonia or appendicitis), monitor chronic diseases (like rheumatoid arthritis or lupus), or evaluate how well you’re healing after surgery or an injury.

What to Expect Before the Test

You may be asked to fast for a few hours before the test, but this is not always required. Bring any medications you’re currently taking, as some may affect results. Avoid strenuous activity or excessive stress 24 hours before testing.

What Happens During the Test

A healthcare provider will draw blood from a vein in your arm using a small needle. You may feel a slight pinch, but it usually doesn’t cause significant discomfort. The blood sample is then sent to a lab for analysis.

What the Results Mean

CRP levels vary depending on your health. Higher levels may indicate inflammation, while lower levels suggest minimal or no inflammation. Your doctor will interpret results in the context of your medical history and symptoms.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

CRP (Nephelometry)

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 time. Your doctor will contact you once they’re ready to discuss the results.
Can I eat or drink before my CRP test?
While fasting isn’t always required, it’s best to avoid heavy meals or alcohol 24 hours before testing to ensure accurate results. Ask your doctor or lab for specific instructions.
Does my CRP level change with age?
Yes, CRP levels can naturally increase with age due to chronic, low-level inflammation. However, elevated levels in older adults may still indicate underlying health concerns, so it’s important to discuss findings with your doctor.
  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