Potassium in Cerebrospinal Fluid (CSF)
This test measures the amount of potassium, a mineral electrolyte, found in your cerebrospinal fluid (the fluid surrounding your brain and spinal cord). It helps assess conditions affecting fluid balance, nerve function, or potential infections.
["Potassium levels in CSF can signal neurological or infectious issues."]
Key facts at a glance
- LOINC
- 2819-1
- Short code
- Potassium CSF-sCnc
- Synonyms
- Potassium CSF-sCnc
- Category
- electrolyte
- Sample
- csf
- Container
- Sterile tube
- Units
- N/A
- Ref low
- 3.5
- Ref high
- 5
- Critical range
- 2.5 N/A – 6.5 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 84132
- SNOMED
- 110742001
- Specimen volume
- 1-2 mL
- Stability
- Immediate analysis required, Refrigerated: 1h
- Hemolysis max
- 200
- TAT
- 4–24 hours
- Order
- routine
Why This Test Might Be Ordered
Your healthcare provider may recommend this test if you have symptoms like severe headaches, neck stiffness, confusion, seizures, or signs of meningitis, encephalitis, or other neurological disorders. It may also be part of a broader evaluation for conditions like brain swelling (cerebral edema), subarachnoid hemorrhage, or metabolic imbalances.
What to Expect Before the Test
No special preparation is typically needed. You may have a small needle inserted into your lumbar spine to collect a small sample of CSF. This procedure is usually done in a hospital setting under sterile conditions.
What the Results Mean
CSF potassium levels can vary based on underlying conditions. Abnormally low levels (hypokalemia) may indicate conditions like meningitis, brain tumors, or certain metabolic disorders. Abnormally high levels (hyperkalemia) could suggest severe infections, brain trauma, or other neurological emergencies.
Common Conditions Affecting Results
Changes in CSF potassium can be linked to infections (e.g., bacterial or viral meningitis), inflammatory diseases, brain injuries, or certain medications. Always discuss your results with your healthcare provider for personalized interpretation.
Reference range
Adult: 3.5-5.0 mmol/LN/A
No special preparation required. Stay well hydrated.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
This test is critical for diagnosing and monitoring neurological conditions that alter fluid or electrolyte balance in the brain. It helps guide treatment decisions, such as managing infections, reducing swelling, or addressing metabolic disturbances.
Short name
CSF Potassium
Frequently asked questions
What is the normal range for CSF potassium?
How long does it take to get the results of this 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