C-reactive protein (CRP) in 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 doctors assess inflammation, often used to monitor conditions like infections or autoimmune diseases."]
Key facts at a glance
- LOINC
- 7593-7
- Short code
- CHIHIST
- Synonyms
- Chili Pepper BasoBnd Ab Qn
- Category
- chemistry
- Sample
- whole-blood
- Container
- Heparinized (green-top) tube for whole blood basophil histamine release testing
- Units
- N/A
- Ref low
- 0
- Ref high
- 0.1
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- ≥ 2 years
- Method
- Allergen-specific histamine release assay using whole blood basophil activation
- CPT
- 86003
- SNOMED
- 395140001
- Specimen volume
- 5-10 mL of whole blood
- Stability
- Specimen should be processed within 2-4 hours of collection; keep at room temperature (18-25°C); do not refrigerate or freeze
- Hemolysis max
- 100
- Lipemia max
- 100
- Icterus max
- 50
- TAT
- 24–72 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 arthritis or heart disease, or evaluate symptoms such as fever, pain, or swelling that suggest an infection or other issues.
What to Expect Before the Test
No special preparation is usually needed. You may be asked to fast before the test, depending on the lab’s instructions. Bring any medications you’re taking to your appointment.
What Happens During the Test?
A healthcare professional will draw blood from a vein in your arm. You may feel a small pinch, but it usually doesn’t cause discomfort. The blood sample is then sent to the lab for analysis.
What Are the Results?
Results are typically reported in milligrams per liter (mg/L). Higher levels may indicate inflammation, infection, or other health concerns. Your doctor will interpret the results in the context of your medical history and symptoms.
Reference range
Negative: <0.1 ng/mL; results interpreted qualitatively as positive or negative for chili pepper sensitivityN/A
No fasting required. Patients should discontinue antihistamines, corticosteroids, and other allergy medications for 5-7 days prior to testing as recommended by the ordering physician. Inform provider of any recent allergic reactions or immunotherapy.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
CRP
Frequently asked questions
What does a high CRP level mean?
What does a low CRP level mean?
Can lifestyle changes affect CRP levels?
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 15, 2026. · Read our editorial policy