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C-Reactive Protein (CRP) Fluid Analysis (Quantitative)

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

This test measures the amount of C-reactive protein in your blood, a marker often checked for signs of inflammation.

Quick summary

["CRP helps track inflammation, which can signal infections, injuries, or other health conditions."]

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

Key facts at a glance

LOINC
98987-1
Short code
CRP Fld-aCnc
Synonyms
CRP Fld-aCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
0
Ref high
3
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
86140
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 Is Done

Your doctor may order this test to monitor conditions like arthritis, heart disease, infections, or to check for inflammation after surgery or injury. It can also help evaluate responses to treatments.

What to Expect Before the Test

No special preparation is needed, but you may be asked to fast for 8–12 hours before the draw if your lab requires it. Wear a loose shirt for easy access to your arm.

A healthcare provider will draw blood from a vein in your arm using a small needle. You may feel a brief pinch, but the procedure is quick.

The blood sample is sent to a lab where it’s analyzed for CRP levels using an immunoassay method.

Higher-than-normal CRP levels may indicate inflammation, but they don’t always point to a specific cause. Your doctor will interpret results in relation to your symptoms and medical history.

Normal CRP levels vary by age and health status, so your doctor will compare your result to your baseline or clinical context.

Reference range

Normal: <3.0 mg/LN/A

Specimen: serum

No special preparation required. CRP may be affected by acute illness.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

CRP Level (Serum/Plasma)

Frequently asked questions

What causes CRP levels to rise?
CRP increases in response to infections (bacterial, viral), injuries, surgeries, or autoimmune diseases. Stress, obesity, or certain medications (e.g., steroids) can also affect levels.
Can CRP levels be affected by diet or lifestyle?
Yes, diet, exercise, and weight management may influence CRP levels. For example, reducing processed foods and increasing omega-3s (found in fish) may help lower inflammation.
How often should CRP be checked?
Your doctor will determine how often to check CRP based on your condition. Some patients get it yearly or more frequently if they have chronic inflammation or heart disease.
  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