Glucose in Cerebrospinal Fluid (CSF) by Substance Concentration
This test measures the amount of glucose (sugar) found in your cerebrospinal fluid (the fluid surrounding your brain and spinal cord). It helps assess conditions affecting the blood-brain barrier or the brain’s metabolic health.
["A glucose test in your spinal fluid can help diagnose or monitor neurological conditions."]
Key facts at a glance
- LOINC
- 76671-7
- Short code
- Glucose tube3 CSF-sCnc
- Synonyms
- Glucose tube3 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 This Test Is Done
Your healthcare provider may order this test if you have symptoms like headaches, confusion, seizures, or neurological issues that could suggest conditions such as meningitis, brain infections, or metabolic disorders. It may also be used to evaluate patients with traumatic brain injuries or those on certain medications that affect glucose levels.
What to Expect Before the Test
You’ll likely have a spinal tap (lumbar puncture) where a small needle is inserted into your lower back to collect a sample of CSF. The procedure is usually quick and may cause mild discomfort. No special preparation is needed, but inform your doctor about any medications you’re taking.
What the Test Results Mean
Glucose levels in CSF can differ from blood glucose levels. Low levels may indicate conditions like meningitis, brain tumors, or certain metabolic disorders. High levels could suggest conditions like diabetes-related complications or certain infections. Your results will be interpreted by your healthcare provider in the context of your full medical history.
Common Conditions Monitored
This test is often used to diagnose or monitor conditions like bacterial or viral meningitis, subarachnoid hemorrhage, multiple sclerosis, or other neurological diseases that affect glucose metabolism in the CSF.
Reference range
Fasting: 70-100 mg/dLN/A
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.
Clinical Significance: Glucose in CSF plays a critical role in identifying abnormalities in the brain’s environment. Abnormal glucose levels can signal inflammation, infection, or metabolic disturbances that may require immediate medical attention. Your provider will use these results alongside other tests and symptoms to guide diagnosis and treatment.
Short name
CSF Glucose
Frequently asked questions
What does a low CSF glucose level mean?
How is this test different from a blood glucose test?
Can I eat or drink before this test?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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