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Neutrophil Segment Count in Cerebrospinal Fluid (CSF)

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

This test measures the number of neutrophils, a type of white blood cell, in your cerebrospinal fluid (CSF). Neutrophils help fight infections.

Quick summary

["Neutrophils in CSF can indicate infections or inflammation in your brain or spinal cord."]

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

Key facts at a glance

LOINC
35011-6
Short code
Neuts Seg # CSF
Synonyms
Neuts Seg # CSF
Category
chemistry
Sample
csf
Container
Sterile tube
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
1-2 mL
Stability
Immediate analysis required, Refrigerated: 1h
Hemolysis max
200
TAT
4–24 hours
Order
routine

Why Might This Test Be Ordered?

Your healthcare provider may order this test if you have symptoms like severe headaches, neck stiffness, fever, or neurological issues that suggest an infection (such as meningitis) or inflammation in the brain or spinal cord. It’s also used to monitor conditions like multiple sclerosis or other neurological disorders.

What Does a High or Low Neutrophil Count Mean?

A high neutrophil count in CSF often suggests an infection (e.g., bacterial meningitis) or severe inflammation. A low count may indicate viral meningitis, autoimmune conditions, or other non-infectious causes like certain cancers or immune disorders.

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 analyzed in a lab to count the neutrophils among other white blood cells.

What Are Common Causes of Abnormal Results?

Abnormal neutrophil counts in CSF can result from infections (bacterial, viral, or fungal), autoimmune diseases, tumors, or other neurological conditions. Always discuss results with your provider.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Neutrophil Count in CSF

Frequently asked questions

What happens if my neutrophil count in CSF is high?
A high neutrophil count in CSF often signals a bacterial infection, such as meningitis. Your doctor may recommend antibiotics or further testing to identify the cause and guide treatment.
What if my neutrophil count in CSF is low?
A low neutrophil count in CSF may suggest viral meningitis, autoimmune reactions, or other non-infectious causes. Your provider will work with you to determine the best next steps based on your symptoms and test results.
How often should I get this test?
This test is typically done as needed based on your symptoms or medical condition. Your healthcare provider will decide how often to repeat it, if at all.
  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