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C-Reactive Protein (CRP) by Turbidimetry

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 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
97553-2
Short code
DO-Hgb MFr BldCV
Synonyms
DO-Hgb MFr BldCV
Category
hematology
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Ref low
12
Ref high
17.5
Critical range
7 N/A – 20 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
85018
SNOMED
900000000000003004
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 Is This Test Done?

Your healthcare provider may order a CRP test to check for signs of inflammation, monitor chronic conditions like rheumatoid arthritis or lupus, or evaluate symptoms such as fever, joint pain, or swelling that might indicate an infection or other inflammatory process.

What to Expect Before the Test

No special preparation is usually needed. You may be asked to fast for 8–12 hours before the test if it involves drawing blood from a vein. If you’re taking certain medications that affect inflammation, your provider may ask you to stop them temporarily.

What Happens During the Test

A healthcare professional will insert a small needle into a vein in your arm to draw a blood sample. You may feel a brief pinch, but the procedure is quick and usually painless. The blood is then sent to a lab for analysis.

What the Results Mean

Results are reported in milligrams per liter (mg/L). Higher than normal levels may suggest inflammation, infection, or other health issues. Your provider will interpret the results in the context of your overall health and symptoms.

Reference range

Adult males: 13.5-17.5 g/dL; Females: 12.0-16.0 g/dLN/A

Specimen: whole-blood

No special preparation usually required. Stay well hydrated. Inform your healthcare provider of all medications and supplements you are taking.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

CRP Blood Test

Frequently asked questions

Will I need to avoid certain foods or drinks before the test?
If your test involves fasting, avoid eating or drinking (except water) for 8–12 hours beforehand. If fasting isn’t required, you can eat and drink normally. Always follow your provider’s specific instructions.
Can CRP levels change based on my diet or exercise?
Yes, lifestyle factors like diet, exercise, and stress can influence inflammation. A healthy diet rich in fruits, vegetables, and omega-3 fatty acids may help lower CRP levels, but results depend on the overall health of your body and any underlying conditions.
What if my CRP levels are high but I don’t have obvious symptoms?
High CRP levels can sometimes occur without clear symptoms, especially in chronic conditions. Your provider may recommend further testing or lifestyle adjustments to manage inflammation. It’s important to discuss your results with them to understand 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