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Cerebrospinal Fluid Cell Count (with Differential)

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

This test measures the number of white blood cells and their types in your cerebrospinal fluid (CSF), which is the fluid surrounding your brain and spinal cord. It helps identify infections, inflammation, or other conditions affecting the central nervous system.

Quick summary

["Understanding your CSF cell count can help diagnose or monitor conditions like meningitis, multiple sclerosis, or brain injuries."]

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

Key facts at a glance

LOINC
57736-1
Short code
CD154
Synonyms
CD154 cells NFr Fld
Category
chemistry
Sample
serum
Container
Sterile body fluid collection container or appropriate anticoagulant tube (e.g., EDTA) as specified by performing laboratory
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
Flow cytometry
CPT
88184
SNOMED
363787002
Specimen volume
1-5 mL of body fluid depending on fluid type and laboratory requirements
Stability
Process within 4-6 hours of collection if maintained at room temperature; refer to performing laboratory guidelines for specific stability requirements.
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
24–72 hours
Order
routine

Why This Test Is Done

Your doctor may order this test if you have symptoms like severe headaches, neck stiffness, fever, confusion, or neurological issues. It’s often done when other tests, like bloodwork or imaging, suggest possible infections, bleeding, or swelling in the brain or spinal cord.

What to Expect Before the Test

You’ll likely have a lumbar puncture (spinal tap), where a small needle is inserted into your lower back to collect CSF. You may feel pressure or a mild ache, but it’s usually quick and done in a hospital setting. Rest assured, this procedure is safe and monitored by medical professionals.

What the Results Mean

The test looks at the total number of cells and breaks them down into types (like neutrophils, lymphocytes, or monocytes). High cell counts, especially certain types, can signal infections (e.g., bacterial or viral meningitis), inflammation, or bleeding. Low counts might indicate a lack of infection or other neurological issues.

Common Conditions Monitored

This test is critical for diagnosing or managing conditions like meningitis (bacterial or viral), multiple sclerosis, subarachnoid hemorrhage, or other brain/spinal cord disorders. It helps doctors track how your condition is progressing or responding to treatment.

Reference range

Reference range established by performing laboratory; interpret results in context of clinical findings.N/A

Specimen: serum

No special patient preparation required.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Elevated cell counts, particularly neutrophils, often point to bacterial infections such as meningitis. Lymphocytes may suggest viral infections or autoimmune conditions. Monocytes could indicate chronic inflammation or other systemic issues. Abnormal cell types or ratios can guide treatment decisions, such as starting antibiotics or steroids.

Short name

CSF Cell Count/Diff

Frequently asked questions

How is CSF collected?
CSF is collected through a procedure called a lumbar puncture, where a needle is inserted into your lower back to draw fluid from the spinal canal. This is typically done in a hospital setting under sterile conditions.
Will the test hurt?
You may feel mild pressure or discomfort during the procedure, but most people describe it as a brief, sharp sensation. Numbing medication can be used to reduce any discomfort. Recovery is usually quick, and you can return to normal activities soon after.
Can I eat or drink before the test?
You can usually eat and drink normally before this test unless your doctor advises otherwise. Since it involves a spinal tap, fasting isn’t required, but follow any specific instructions your healthcare provider gives you to ensure accuracy.
  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