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C-reactive protein in sinus fluid (CRP in sinus fluid)

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

This test measures the level of C-reactive protein (CRP) in fluid collected from your sinuses. CRP is a protein your body produces in response to inflammation.

Quick summary

["This test helps assess sinus infection severity and inflammation."]

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

Key facts at a glance

LOINC
30588-8
Short code
CT Sinuses
Synonyms
CT Sinuses
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ct
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 this test if you have symptoms like nasal congestion, facial pain, or thick mucus that suggests a sinus infection. It helps determine whether your symptoms are due to inflammation or infection and guides treatment decisions.

What does the result mean?

Higher levels of CRP in sinus fluid often indicate active inflammation or infection. While reference ranges can vary, elevated levels may suggest a need for further medical evaluation or treatment with antibiotics or other therapies.

How is the test performed?

A healthcare professional will collect fluid from your sinuses using a thin tube or catheter. The fluid is then sent to a lab for testing. The test measures CRP levels, which can be compared to standard reference values for interpretation.

What are common causes of elevated CRP in sinus fluid?

Elevated CRP in sinus fluid is commonly seen in sinus infections (bacterial, viral, or fungal), chronic sinusitis, or other inflammatory conditions affecting the sinuses. Other conditions, such as allergies or structural issues, may also contribute to sinus inflammation.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Sinus fluid CRP

Frequently asked questions

What does a high CRP level in sinus fluid mean?
A high CRP level suggests significant inflammation or infection in your sinuses. This may indicate a bacterial infection or severe sinusitis, but it doesn’t always confirm the exact cause. Your provider will consider the full clinical picture and may recommend additional tests or treatments.
Does this test replace a nasal culture?
No, this test measures CRP levels in sinus fluid but doesn’t identify the specific bacteria or virus causing the infection. A nasal culture would provide that information. CRP testing is often used alongside other tests to assess inflammation and guide treatment decisions.
How soon will I get results?
Results from this test are typically available within 1–3 business days, depending on lab processing times. Your healthcare provider will discuss the results with you during your follow-up visit.
  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