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Glucose in Cerebrospinal Fluid (CSF) by Substance Concentration

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

This test measures the amount of glucose (sugar) found in your spinal fluid, which helps assess conditions affecting the brain, spinal cord, or surrounding areas.

Quick summary

["Glucose levels in CSF can indicate inflammation, infection, or other neurological issues."]

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

Key facts at a glance

LOINC
76670-9
Short code
Glucose tube2 CSF-sCnc
Synonyms
Glucose tube2 CSF-sCnc
Category
glucose
Sample
csf
Container
Sterile tube
Units
N/A
Ref low
70
Ref high
100
Critical range
50 N/A – 400 N/A
Fasting
true
Population
adult
Sex
all
Age range
18–65 years
CPT
82947
SNOMED
260395008
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 doctor may order this test to investigate symptoms like headaches, neck stiffness, confusion, or neurological problems. It can also help diagnose conditions such as meningitis, encephalitis, or subarachnoid hemorrhage.

What to Expect Before the Test

No special preparation is needed. You’ll have a small needle inserted into your back to collect a sample of spinal fluid. You may feel a brief pinch, but the procedure is quick and usually painless. You’ll lie on your side with your knees bent.

What Happens During the Test?

The healthcare provider will insert a needle into your lower back to collect a small amount of cerebrospinal fluid. The sample is then sent to the lab for analysis. The test itself takes only a few minutes.

What Are Possible Results?

Results are compared to standard reference ranges for glucose in CSF. Low levels may suggest infection, high levels could indicate bleeding or metabolic issues. Your doctor will interpret results in the context of your symptoms and medical history.

Reference range

Fasting: 70-100 mg/dLN/A

Specimen: csf

Fasting for 8-12 hours required. Water is permitted. Avoid chewing gum and smoking before the test.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Abnormal glucose levels in CSF can signal serious conditions like bacterial or viral meningitis, where glucose levels often drop due to inflammation. Elevated levels might be seen in conditions such as subarachnoid hemorrhage or certain metabolic disorders. Always discuss results with your healthcare provider for accurate interpretation.

Short name

CSF Glucose

Frequently asked questions

What Does a Low CSF Glucose Level Mean?
A low glucose level in CSF is often associated with infections like meningitis or encephalitis, where the body’s immune response consumes glucose. It’s important to follow up with your doctor to determine the cause and appropriate treatment.
What Does a High CSF Glucose Level Mean?
High glucose levels in CSF can occur in conditions such as subarachnoid hemorrhage or certain metabolic disorders. Your doctor will consider other factors, like symptoms and lab results, to determine the underlying issue.
Is There Any Risk or Side Effect?
The procedure is generally safe, but you may experience mild soreness or bruising at the injection site. Rarely, there could be complications like headache or infection, but these are uncommon. Always inform your doctor if you experience severe pain or unusual symptoms after the test.
  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