Cerebrospinal Fluid (CSF) White Blood Cell Count (Qualitative)
This test checks the number of white blood cells in your spinal fluid, which helps identify infections, inflammation, or other conditions affecting your brain or spinal cord.
["A white blood cell count in CSF can signal infections, bleeding, or immune responses in the central nervous system."]
Key facts at a glance
- LOINC
- 33057-1
- Short code
- Heinz Bod/RBC NFr Bld Smear
- Synonyms
- Heinz Bod/RBC NFr Bld Smear
- Category
- chemistry
- Sample
- whole-blood
- Container
- Lavender-top (EDTA)
- Units
- N/A
- Ref low
- 4.2
- Ref high
- 5.9
- Critical range
- 2 N/A – 7 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- microscopy-light
- CPT
- 85041
- SNOMED
- 900000000000003001
- 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
Why This Test Might Be Ordered
Your doctor may recommend this test if you have symptoms like severe headaches, neck stiffness, fever, confusion, or neurological issues that suggest an infection, inflammation, or other spinal fluid abnormalities. It’s often done when other tests or conditions aren’t clearly explaining your symptoms.
How the Test Works
A small amount of spinal fluid is collected through a procedure called a lumbar puncture (spinal tap). The fluid is then examined under a microscope to count white blood cells. This test is qualitative, meaning it provides a yes/no or presence/absence result rather than a specific number.
What to Expect Before the Test
You may be asked to empty your bladder before the procedure. Avoid heavy lifting or strenuous activity for 24 hours afterward to reduce the risk of complications like headaches or spinal fluid leaks.
What to Expect During the Test
The procedure involves inserting a needle into your lower back to collect spinal fluid. You may feel pressure or a slight sting, but it usually doesn’t cause pain. You’ll lie on your side with your knees bent, and the doctor will guide the needle carefully.
Reference range
Adult males: 4.2-5.9; Females: 3.8-5.1 x 10^12/LN/A
No special preparation required. Stay well hydrated.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Elevated white blood cells in CSF often indicate an infection (like meningitis), inflammation (such as multiple sclerosis), or bleeding (like subarachnoid hemorrhage). Normal results suggest no significant white blood cell presence, which may rule out these conditions. Always discuss results with your doctor, as they’ll consider your symptoms and other tests.
Short name
CSF WBC Qual
Frequently asked questions
What does a positive result mean?
How long does it take to get results?
Can I eat or drink before this test?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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