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C-reactive protein (CRP) concentration, mass concentration

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

This test measures the level 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, autoimmune diseases, or after surgery."]

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

Key facts at a glance

LOINC
7365-0
Short code
Cocksfoot IgG Qn
Synonyms
Cocksfoot IgG Qn
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 Is This Test Done?

Your healthcare provider may order CRP testing to check for signs of inflammation, monitor chronic conditions like arthritis or heart disease, or evaluate responses to treatments. It can also help identify infections or other inflammatory processes in your body.

What to Expect Before the Test

CRP is typically drawn from a blood sample. You may have a small needle inserted into your arm, and you’ll feel a brief pinch. No special preparation is needed unless instructed otherwise.

What the Results Mean

Higher CRP levels often indicate inflammation, but results alone don’t diagnose a specific condition. Your provider will compare your results with your medical history and other tests to understand what’s happening in your body.

Common Conditions Monitored

CRP is used to monitor conditions such as rheumatoid arthritis, heart disease, infections, or after surgeries like joint replacements to check for complications.

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

Frequently asked questions

What causes CRP levels to change?
CRP levels can rise due to infections (like pneumonia or urinary tract infections), autoimmune diseases (like lupus or rheumatoid arthritis), injuries, surgeries, or other inflammatory conditions. Stress, certain medications, or recent illnesses may also temporarily affect results.
How often should I get this test?
Your provider will determine how often you need CRP testing based on your health condition. Some people get it yearly or more frequently if they have chronic inflammation or a history of heart disease or infections.
Can diet or lifestyle affect CRP levels?
Yes, diet, exercise, and weight management can influence CRP levels. Reducing inflammation through a balanced diet, regular physical activity, and avoiding smoking may help lower 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 17, 2026. · Read our editorial policy