Home/Lab Tests/The CSF Albumin test measures the amount of albumin protein in the clear fluid that surrounds and protects your brain and spinal cord. Albumin, which is made mainly by the liver, normally passes into this fluid in only small amounts through the blood-brain barrier, a protective filter that keeps harmful substances away from the brain while allowing nutrients through. Using a laboratory technique called electrophoresis, this test helps your doctor evaluate how well that barrier is working.

The CSF Albumin test measures the amount of albumin protein in the clear fluid that surrounds and protects your brain and spinal cord. Albumin, which is made mainly by the liver, normally passes into this fluid in only small amounts through the blood-brain barrier, a protective filter that keeps harmful substances away from the brain while allowing nutrients through. Using a laboratory technique called electrophoresis, this test helps your doctor evaluate how well that barrier is working.

Published: July 31, 2026Updated: August 17, 2026

This test measures the level of albumin in your cerebrospinal fluid (CSF) using a method called electrophoresis, helping your doctor assess whether your blood-brain barrier is healthy or damaged.

Quick summary

{"Albumin in CSF helps doctors evaluate if the blood-brain barrier is functioning properly","This test can detect CSF leakage, meningitis, or other neurological conditions","The test uses a sample of cerebrospinal fluid collected via lumbar puncture","Results are often compared with blood albumin levels for better interpretation","Abnormal results may indicate infection, inflammation, or leak in the CSF system"}

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC: 2861-3
Short code: CSF Albumin
Synonyms: Albumin CSF Elph-mCnc
Category: chemistry
Sample: csf
Container: Sterile CSF collection tube (plain sterile container or tube with no additives)
Units: not specified
Ref low: 0
Ref high: 35
Critical range: 1.5 not specified – 100 not specified
Fasting: false
Population: adult
Sex: all
Age range: ≥ 0 years
Method: electrophoresis
CPT: 82040 (Albumin, CSF)
SNOMED: 308441001
Specimen volume: 1-2 mL of CSF minimum
Stability: Store at 2-8°C if analysis delayed; analyze within 24-48 hours. Freeze at -20°C for longer storage.
Hemolysis max: 200
TAT: 24–72 hours
Order: routine

What is this test?

The CSF Albumin test measures the amount of albumin protein in your cerebrospinal fluid (CSF). CSF is the clear fluid that surrounds and protects your brain and spinal cord. This test uses a technique called electrophoresis to separate and measure the albumin protein.

Why is it important?

Albumin is produced mainly by the liver and normally enters the CSF in small amounts through the blood-brain barrier. This test helps doctors understand how well the blood-brain barrier is working. The blood-brain barrier is like a protective filter that keeps harmful substances away from the brain while allowing necessary nutrients to pass through.

How is the sample collected?

A healthcare provider collects cerebrospinal fluid using a procedure called lumbar puncture (spinal tap). During this procedure, a thin needle is inserted into the lower back to withdraw a small amount of CSF. The sample is then sent to a laboratory for analysis using electrophoresis.

What do the results mean?

Your doctor will compare your CSF albumin level with your blood albumin level. This ratio helps determine if the blood-brain barrier is healthy or damaged. Elevated CSF albumin may indicate conditions that affect the barrier's integrity, while very low levels are less common but may have their own clinical significance.

Reference range

0-35 mg/dLnot specified

Specimen: csf

No special preparation required; specimen obtained via lumbar puncture

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Elevated CSF albumin levels may indicate: blood-brain barrier disruption due to infection (meningitis, encephalitis), inflammatory conditions like multiple sclerosis, brain tumors, cerebral hemorrhage, or CSF leakage (such as from the nose or ear). The test is particularly useful in diagnosing and monitoring conditions that affect the protective barriers around the brain and spinal cord.

This test helps healthcare providers differentiate between various neurological conditions, assess the severity of brain inflammation, and monitor treatment response in certain disorders. It is often used alongside other CSF tests (like glucose and protein) and clinical findings to make a complete assessment.

Frequently asked questions

Is the lumbar puncture procedure painful?

You may feel some discomfort or pressure during the lumbar puncture. Local anesthetic is usually used to numb the area, which helps reduce pain. Most patients describe it as a brief sting followed by a feeling of pressure. The procedure typically takes only a few minutes.

Are there any risks after the procedure?

Some people may experience a headache after a lumbar puncture, which usually resolves with rest and hydration. Serious complications are rare but can include infection, bleeding, or nerve damage. Contact your healthcare provider if you experience severe headache, fever, or unusual symptoms.

How long does it take to get results?

Results are typically available within a few days, as the electrophoresis process requires specialized laboratory equipment and expertise. Your healthcare provider will discuss the results with you during a follow-up appointment.

Do I need to fast before this test?

Fasting is not typically required for a CSF albumin test. However, always follow your healthcare provider's specific instructions. Make sure to inform your doctor about any medications or supplements you are taking.

Can this test diagnose multiple sclerosis?

While elevated CSF albumin (specifically the albumin quotient) can be found in multiple sclerosis, it is not used alone for diagnosis. Doctors consider this test along with clinical symptoms, MRI findings, and other laboratory tests to make a complete diagnosis.

Sources

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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 17, 2026. · Read our editorial policy