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C-reactive protein (CRP) mass concentration in serum/plasma

Published: August 9, 2026Updated: August 17, 2026

This test measures the amount of C-reactive protein, a protein produced by the liver in response to inflammation in your body.

Quick summary

["CRP helps doctors assess inflammation, often used to monitor conditions like infections or autoimmune diseases."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
107446-7
Short code
CK MM DBS-cCnc
Synonyms
CK MM DBS-cCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
22
Ref high
198
Critical range
— – 10000 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
82553
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 This Test Might Be Ordered

Your healthcare provider may order a CRP test to check for signs of inflammation, monitor chronic conditions like arthritis or heart disease, or evaluate responses to treatments. It can also help diagnose infections or identify risks for conditions like heart disease or certain cancers.

What to Expect During the Test

A blood sample is taken from a vein, usually in your arm. You may feel a small pinch, but it typically doesn’t cause significant discomfort. The blood is sent to a lab for analysis.

Factors That Can Affect Results

Several factors can influence CRP levels, including recent infections, injuries, stress, certain medications, or underlying health conditions. Smoking, obesity, and high cholesterol can also play a role.

Common Uses and Interpretation

While CRP levels alone don’t diagnose specific conditions, they are often used alongside other tests. High levels may suggest inflammation, while low levels might indicate no active inflammation. Your provider will interpret results in the context of your overall health and symptoms.

Reference range

Adult males: 22-198 U/L; Females: 22-198 U/LN/A

Specimen: serum

No special preparation required. Inform provider of any chest pain or symptoms.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

CRP (Serum/Plasma)

Frequently asked questions

What does a high CRP level mean?
A high CRP level often signals inflammation in the body, which can be caused by infections, autoimmune diseases, or other inflammatory conditions. It’s not a definitive diagnosis but can guide further testing or treatment adjustments.
How often should I get this test?
Frequency depends on your health condition and treatment plan. Your healthcare provider will determine how often you need this test based on your specific needs, such as monitoring chronic diseases or response to treatment.
Can diet or lifestyle changes affect CRP levels?
Yes, lifestyle factors like diet, exercise, smoking, and weight can influence CRP levels. Adopting an anti-inflammatory diet, staying active, and avoiding smoking may help lower CRP levels over time, but results vary among individuals.
  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 17, 2026. · Read our editorial policy