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Cerebrospinal Fluid Cytology (Cell Count or Differential)

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

This test examines cells found in your cerebrospinal fluid (CSF), which surrounds your brain and spinal cord. It helps identify infections, inflammation, or other conditions affecting the central nervous system.

Quick summary

["CSF cell counts and types can reveal causes of headaches, neurological symptoms, or other concerns."]

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

Key facts at a glance

LOINC
42209-7
Short code
Cyto CSF
Synonyms
Cyto CSF
Category
chemistry
Sample
csf
Container
Sterile tube
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
cyto-stain
Specimen volume
1-2 mL
Stability
Immediate analysis required, Refrigerated: 1h
Hemolysis max
200
TAT
4–24 hours
Order
routine

What Is a CSF Cell Count/Differential Used For?

A CSF cell count measures the total number of cells in your CSF, while a differential breaks down the types of cells (e.g., white blood cells, red blood cells, or other cells) present. This helps doctors diagnose conditions like meningitis, brain tumors, or multiple sclerosis.

How Is This Test Performed?

A small amount of CSF is collected through a procedure called a lumbar puncture (spinal tap). The sample is then sent to a lab for microscopic analysis to count and identify cell types.

When Might You Need This Test?

Your doctor may order this test if you have symptoms like severe headaches, neck stiffness, confusion, fever, or neurological issues (e.g., numbness, weakness). It’s also used in investigations for suspected infections, bleeding, or tumors in the brain or spinal cord.

What Are Possible Results?

Results may show elevated or low cell counts, abnormal cell types, or the presence of specific cells (e.g., white blood cells for infection, red blood cells for bleeding). Exact values depend on the reason for testing and clinical context.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

CSF Cell Count/Differential

Frequently asked questions

Why do I need this test if I only have mild symptoms?
Even mild symptoms—such as persistent headaches, fatigue, or unexplained neurological changes—can sometimes indicate underlying issues like inflammation, infection, or other conditions that require further investigation. Your doctor may recommend this test to rule out serious causes.
What happens during the lumbar puncture procedure?
The procedure involves inserting a needle into your lower back to collect CSF. You’ll lie on your side with your knees bent, and the area is numbed with local anesthesia. The process usually takes about 15–30 minutes, and you may feel mild pressure or discomfort afterward.
How long will it take to get my results?
Results are typically available within 1–3 business days, depending on lab processing times. Your doctor will discuss the findings with you during a 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