C-reactive protein (CRP) by nephelometry
This test measures the level of C-reactive protein in your blood, a protein produced by your liver in response to inflammation or infection.
["CRP helps doctors assess inflammation, track infections, or monitor conditions like arthritis or heart disease."]
Key facts at a glance
- LOINC
- 36085-9
- Short code
- MRA Neck ves
- Synonyms
- MRA Neck ves
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- 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
- Method
- mr-angio
- CPT
- 82553
- 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 This Test Is Done
Doctors may order a CRP test to check for signs of inflammation, monitor chronic conditions like rheumatoid arthritis, or evaluate symptoms such as fever, joint pain, or swelling. It can also help determine if you have an infection, such as pneumonia or sepsis, or if your body is reacting to an injury.
How the Test Works
Blood is drawn from a vein, usually in your arm. The sample is then analyzed using nephelometry, a method that measures how much light scatters when it interacts with the CRP protein in your blood.
What to Expect Before the Test
No special preparation is usually needed, but you may be asked to fast for a few hours if your doctor specifies it. Wear comfortable clothing and plan to stay near the testing site for a short time after the draw.
What to Expect During the Test
You’ll lie down or sit comfortably while a healthcare provider inserts a small needle into your vein. You may feel a slight pinch, but the procedure is quick. Once the blood is collected, the needle is removed, and pressure is applied to the site to stop bleeding.
Reference range
Adult males: 22-198 U/L; Females: 22-198 U/LN/A
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 (Nephelometry)
Frequently asked questions
A high CRP level often signals inflammation, which can be caused by infections, autoimmune diseases, or other health issues. Lower levels may indicate fewer inflammatory processes, but results should always be interpreted by your doctor in the context of your overall health and symptoms.
What does a high CRP level mean?
Can I eat or drink before this test?
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 17, 2026. · Read our editorial policy