Cerebrospinal Fluid White Blood Cell Count (with Differential)
This test measures the number of white blood cells in your cerebrospinal fluid (CSF), which is the fluid surrounding your brain and spinal cord. It also provides a breakdown of the types of white blood cells present, helping identify infections, inflammation, or other conditions affecting the central nervous system.
["Assesses inflammation or infection in the brain/spinal cord fluid."]
Key facts at a glance
- LOINC
- 88114-4
- Short code
- WBC CSF Ql Gram Stn
- Synonyms
- WBC CSF Ql Gram Stn
- Category
- chemistry
- Sample
- csf
- Container
- Sterile tube
- Units
- N/A
- Ref low
- 4.5
- Ref high
- 11
- Critical range
- 2 N/A – 30 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- gram-stain
- CPT
- 85004
- SNOMED
- 900000000000003002
- Specimen volume
- 1-2 mL
- Stability
- Immediate analysis required, Refrigerated: 1h
- Hemolysis max
- 200
- TAT
- 4–24 hours
- Order
- routine
Why This Test Is Done
Your doctor may order this test if you have symptoms like headaches, neck stiffness, confusion, fever, or neurological issues. It’s often used to investigate conditions such as meningitis, encephalitis, multiple sclerosis, or other brain/spinal cord disorders.
What to Expect Before the Test
You’ll receive a spinal tap (lumbar puncture) where a small needle is inserted into your lower back to collect CSF. The procedure is quick but may cause mild discomfort. You’ll lie on your side, and a nurse will guide the needle carefully. No special preparation is needed, but inform your doctor about any medications you’re taking.
What the Results Mean
The test results show the total white blood cell count and the proportion of different types (e.g., neutrophils, lymphocytes). Elevated counts may indicate infection or inflammation, while abnormal proportions could suggest conditions like autoimmune diseases or tumors.
Common Conditions Affecting Results
High white blood cell counts in CSF are often linked to infections (e.g., bacterial or viral meningitis), autoimmune diseases (e.g., multiple sclerosis), or tumors. Low counts may suggest bleeding or other neurological issues. Your doctor will interpret results in the context of your symptoms and medical history.
Reference range
Adult: 4.5-11.0 x 10^9/LN/A
No special preparation required. Stay well hydrated.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
This test is critical for diagnosing and monitoring conditions affecting the central nervous system. It helps differentiate between infections, inflammatory diseases, and other neurological disorders by providing detailed information about the immune response in the CSF.
Short name
CSF WBC Count
Frequently asked questions
What causes abnormal white blood cell counts in CSF?
How is this test different from a regular blood white blood cell count?
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 16, 2026. · Read our editorial policy