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C-reactive protein (CRP) by nephelometry

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

This test measures the level of C-reactive protein in your blood, a marker often used to assess inflammation or infection.

Quick summary

["CRP helps track inflammation, guiding decisions about treatments or further testing."]

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

Key facts at a glance

LOINC
101230-1
Short code
Zic4 Ab CSF Ql IB
Synonyms
Zic4 Ab CSF Ql IB
Category
chemistry
Sample
csf
Container
Sterile tube
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ib
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 this test to check for signs of inflammation, infections (like pneumonia or urinary tract infections), or conditions such as autoimmune diseases. It can also help monitor treatment responses, such as for rheumatoid arthritis or heart disease.

What Does a High or Low Level Mean?

Elevated CRP levels often indicate inflammation or infection. Very high levels may suggest severe conditions, while consistently low levels might mean your body is not responding to inflammation as expected. Your results will be interpreted by your provider based on your overall health and symptoms.

How Is This Test Performed?

A blood sample is drawn from a vein, usually in your arm. The sample is then sent to a lab where it is analyzed using nephelometry, a method that measures how particles scatter light to detect protein levels.

What Are Common Causes of Abnormal Results?

Infections (bacterial, viral, or fungal), injuries, surgeries, or certain medical conditions (like heart disease, arthritis, or cancer) can raise CRP levels. Smoking, obesity, or stress may also influence results.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

CRP (Nephelometry)

Frequently asked questions

Will I feel any discomfort during the blood draw?
You may feel a slight pinch or sting when the needle is inserted, but most people describe it as mild discomfort. Afterward, you might have a small bruise or soreness at the site, which usually goes away quickly.
How soon will I get my results?
Results are typically available within 24 to 48 hours, depending on your lab’s processing schedule. Your provider will discuss the findings with you during your follow-up visit.
Can I eat or drink before this test?
You can eat and drink normally before this test unless your provider gives specific instructions. Fasting is not required for CRP testing.
  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