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

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

This test measures a protein produced by your liver in response to inflammation or infection. It helps doctors assess whether you have low-grade inflammation that may not be causing obvious symptoms.

Quick summary

["CRP helps track subtle inflammation, often used alongside other tests for conditions like heart disease or autoimmune disorders."]

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

Key facts at a glance

LOINC
75732-8
Short code
HTR2C c.-759C>T Bld/T Ql
Synonyms
HTR2C c.-759C>T Bld/T Ql
Category
chemistry
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
molgen
Specimen volume
3 mL
Stability
Room temperature: 4h, Refrigerated: 24h
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

What Is CRP Used For?

High-sensitivity CRP (hs-CRP) is particularly useful for monitoring chronic inflammation in conditions like cardiovascular disease, where inflammation may not be immediately visible. It can also be part of a broader evaluation for autoimmune diseases or after certain surgeries to check for lingering inflammation.

How Is CRP Different from Standard CRP?

High-sensitivity CRP is more sensitive than standard CRP, meaning it can detect smaller amounts of inflammation in your blood. This makes it useful for conditions where inflammation is present but not severe enough to trigger a strong immune response.

When Might You Need This Test?

Your doctor may order this test if you have risk factors for heart disease, such as high cholesterol, diabetes, or a family history of heart problems. It may also be used to monitor treatment progress for conditions like rheumatoid arthritis or after a heart attack to check for ongoing inflammation.

What Could Affect CRP Levels?

Several factors can influence CRP levels, including infections (like colds or urinary tract infections), injuries, recent surgeries, or certain medications (like steroids). Stress, smoking, and obesity can also temporarily raise CRP levels.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

CRP (High Sensitivity)

Frequently asked questions

Why did my doctor order a high-sensitivity CRP test?
Your doctor may have ordered this test to check for low-level inflammation that could contribute to conditions like heart disease or to monitor how well a treatment is working for an ongoing inflammatory condition. It’s often used alongside other tests to get a clearer picture of your health.
What are the typical reference ranges for CRP?
CRP levels vary and aren’t always reported with a single range. Your doctor will interpret the result based on your overall health, symptoms, and medical history. Very high levels may indicate infection or severe inflammation, while very low levels might suggest the inflammation has improved or is minimal.
Can CRP levels change with diet or lifestyle changes?
Yes, lifestyle factors like diet, exercise, smoking, and weight can influence CRP levels. Reducing inflammation through diet (e.g., Mediterranean diet), staying active, and avoiding smoking may help lower CRP levels over time, though results may take weeks to become noticeable.
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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