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C-reactive protein (CRP) – Serum/Plasma Concentration (High-Sensitivity)

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

This blood test measures a protein produced by your liver in response to inflammation, helping assess low-level inflammation in your body.

Quick summary

["High-sensitivity CRP helps track subtle inflammation that may not show up in other tests."]

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

Key facts at a glance

LOINC
18549-6
Short code
J Pnt ST Amp+20ms L-III
Synonyms
J Pnt ST Amp+20ms L-III
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ekg
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 monitor chronic conditions like heart disease, rheumatoid arthritis, or other inflammatory disorders. It can also help evaluate risk for future health issues, such as heart attacks or strokes, especially in people without obvious symptoms of inflammation.

What to Expect Before the Test

No special preparation is needed. You may have a small needle inserted into a vein in your arm, and a small amount of blood will be drawn. If you’re on blood thinners, let your doctor know before the test.

What the Results Mean

Results are typically reported in milligrams per liter (mg/L). Higher levels may indicate ongoing inflammation, which could signal conditions like infections, autoimmune diseases, or other health concerns. Your doctor will interpret the results in the context of your overall health.

Common Conditions Monitored

This test is often used to track inflammation in conditions like cardiovascular disease, inflammatory bowel disease, or after surgeries to check for complications such as infection or rejection of transplanted organs.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

High-sensitivity CRP (hs-CRP)

Frequently asked questions

Why might my CRP levels be higher than expected?
Several factors can influence CRP levels, including infections, injuries, certain medications, or underlying health conditions like arthritis or heart disease. Stress, smoking, or even recent surgery can also temporarily raise CRP levels.
What should I do if my CRP test results are abnormal?
Your doctor will discuss the results with you and may recommend additional tests or changes to your treatment plan. They’ll consider your overall health, symptoms, and other test results to determine the next steps.
Can lifestyle changes affect my CRP levels?
Yes! Lifestyle factors like diet (e.g., reducing processed foods, increasing fruits and vegetables), exercise, quitting smoking, and managing stress can help lower inflammation and potentially reduce CRP levels over time.
  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