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Cerebrospinal Fluid Turbidity (Turbidimetry)

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

This test measures how cloudy or opaque your cerebrospinal fluid (CSF) is. Turbidity can indicate the presence of abnormal substances, such as blood, protein, or infectious agents.

Quick summary

["Turbidity in CSF may signal underlying conditions that need further evaluation."]

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

Key facts at a glance

LOINC
20512-0
Short code
Turbidity CSF Ql
Synonyms
Turbidity CSF Ql
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 Is This Test Done?

Your healthcare provider may order this test if you have symptoms like severe headaches, neck stiffness, fever, or neurological concerns. Turbidity can help identify infections (such as meningitis), bleeding, or inflammatory processes in the brain and spinal cord.

What Does Turbidity Mean?

A clear CSF sample typically has low turbidity. Increased turbidity suggests possible contamination or abnormal substances. While not a definitive diagnosis, it often prompts additional testing (e.g., cell count, cultures, or protein analysis).

How Is the Test Performed?

A small amount of CSF is collected via a lumbar puncture (spinal tap) using a needle inserted into the spinal canal. The sample is then examined under controlled light conditions to assess cloudiness or opacity.

What Are Common Causes of Turbidity?

Turbidity in CSF can result from conditions like bacterial or viral meningitis, subarachnoid hemorrhage, or other inflammatory or infectious processes. It may also appear with certain medications or lab artifacts.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

CSF Turbidity

Frequently asked questions

What does a high turbidity in CSF usually mean?
A high turbidity may indicate the presence of blood, protein, or infectious material, such as bacteria or viruses. This can signal serious conditions like meningitis, bleeding, or inflammation, so follow-up tests are usually needed.
How long does it take to get results from this test?
Results are typically available within a few hours to a couple of days, depending on the lab’s processing time. Your healthcare provider will discuss the findings with you.
Can diet or medications affect CSF turbidity?
While diet generally does not directly affect CSF turbidity, certain medications (e.g., some antibiotics or contrast dyes) could theoretically alter sample appearance. Always inform your provider about all medications you’re taking.
  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