C-reactive protein (CRP) concentration, 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 inflammation, often used to monitor conditions like infections or autoimmune diseases."]
Key facts at a glance
- LOINC
- 77250-9
- Short code
- MuV IgG+IgM Pnl Ser
- Synonyms
- MuV IgG+IgM Pnl Ser
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 82784
- 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 healthcare provider may order a CRP test to check for signs of inflammation, monitor chronic conditions (such as heart disease or arthritis), or evaluate responses to treatments. It can also help diagnose infections or determine if your body is reacting to an injury or illness.
What to Expect Before the Test
No special preparation is usually needed, but 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 blood from a finger (capillary blood), no fasting is required.
What Happens During the Test?
A healthcare professional will insert a small needle into a vein in your arm or use a finger-prick method to collect a blood sample. The sample is then sent to a lab for analysis.
What Are Possible Results?
Results are reported in milligrams per deciliter (mg/dL) or micrograms per milliliter (µg/mL). Higher-than-normal levels may indicate inflammation, infections, or other health issues, while lower levels may suggest no active inflammation.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
CRP (Serum/Plasma)
Frequently asked questions
CRP is a marker of inflammation and can help diagnose or monitor conditions like rheumatoid arthritis, heart disease, or infections. It’s also used to assess how well a treatment is working or to screen for early signs of disease progression.
A high CRP level often signals inflammation in your body, which can be caused by infections (like pneumonia or urinary tract infections), autoimmune diseases (such as lupus or rheumatoid arthritis), or other inflammatory conditions. Your doctor will consider your symptoms and other test results to determine the cause.
A low CRP level typically means there is little to no inflammation detected in your blood. However, it doesn’t rule out all causes of inflammation, so your doctor may still recommend further testing if needed.
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