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C-reactive protein, serum/plasma concentration (high-sensitivity)

Published: August 9, 2026Updated: August 16, 2026

This test measures a protein in your blood that rises when your body is fighting inflammation, infection, or injury.

Quick summary

["hs-CRP helps track inflammation levels that may not be obvious from other tests."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
31509-3
Short code
M cap caprip Ab Ser-aCnc
Synonyms
M cap caprip Ab Ser-aCnc
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?

Doctors may order hs-CRP to monitor chronic conditions like heart disease or arthritis, check for signs of infection, or assess how well treatments are working. It can also help evaluate risk for future health issues tied to inflammation.

What Does a High or Low Result Mean?

A higher-than-normal hs-CRP suggests increased inflammation, which could signal conditions like heart disease, autoimmune disorders, or infections. A lower result may indicate reduced inflammation, but it doesn’t rule out all causes.

How Is the Test Performed?

A blood sample is drawn from a vein, usually in your arm. The blood is sent to a lab where it’s analyzed to measure hs-CRP levels using a sensitive immunoassay method.

What Should You Know Before Testing?

Avoid strenuous exercise or heavy meals 24 hours before testing to get the most accurate result. If you’re on medications like NSAIDs (e.g., ibuprofen), discuss this with your doctor, as they may affect inflammation markers.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

hs-CRP

Frequently asked questions

Why might my hs-CRP test result be different from what I expected?
Several factors can influence results, including recent illness, stress, diet, or medications. Your doctor may have given specific instructions to follow before testing, so check with them if your result seems unexpected.
Can I eat or drink anything before this test?
Typically, you can have a light snack or drink water, but avoid heavy meals or alcohol 24 hours before testing. Your doctor’s instructions may vary, so follow their guidance.
Does this test detect all types of inflammation?
No, hs-CRP measures a specific protein linked to inflammation. While it’s useful, it doesn’t show the full picture of inflammation in your body—other tests may be needed for a complete assessment.
  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