C-reactive protein (CRP) by turbidimetry (serum/plasma)
This test measures the level of C-reactive protein, a protein produced by the liver in response to inflammation in your body.
["CRP helps identify and monitor inflammation, often used to check for infections, autoimmune conditions, or other health issues."]
Key facts at a glance
- LOINC
- 111435-4
- Short code
- C immitis Ab Msmt Ser
- Synonyms
- C immitis Ab Msmt Ser
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
Why Is This Test Done?
Your doctor may order this test to evaluate signs of inflammation, monitor conditions like infections, arthritis, or other inflammatory diseases, or assess risk factors for heart disease. It can also be used to check for complications after surgery or during treatment for certain illnesses.
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’s part of a metabolic or liver function panel. Avoid strenuous activity or taking anti-inflammatory medications (like ibuprofen) for 48 hours before testing, as they can affect results.
What Happens During the Test?
A small needle will be inserted into a vein in your arm or hand. Blood will be drawn into a tube. The sample is then sent to a lab for analysis using a turbidimetric method to measure CRP levels.
What Are Possible Results?
Results are typically reported in milligrams per liter (mg/L). Higher than normal levels may indicate inflammation, infections, or other health concerns. Your doctor will interpret results in the context of your overall health and medical history.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Elevated CRP levels often signal inflammation, which can be caused by infections (like pneumonia or urinary tract infections), autoimmune diseases (such as rheumatoid arthritis), or other conditions like heart disease or cancer. While CRP doesn’t diagnose a specific condition, it helps guide treatment decisions and monitor disease activity. Low or normal levels suggest minimal inflammation, but further evaluation may still be needed if symptoms persist.
Short name
CRP (Serum/Plasma)
Frequently asked questions
How Long Does It Take to Get Results?
Can I Eat or Drink Before the Test?
What If My CRP Levels Are High?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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