Cerebrospinal Fluid (CSF)

Cerebrospinal fluid (CSF) collection is a test to look at the fluid that surrounds the brain and spinal cord.

CSF acts as a cushion, protecting the brain and spine from injury. The fluid is normally clear. The test is also used to measure pressure in the spinal fluid.

This test is done to measure pressures within the cerebrospinal fluid and to collect a sample of the fluid for further testing. CSF analysis can be used to diagnose certain neurologic disorders, particularly infections (such as meningitis) and brain or spinal cord damage.

Results of CSF Analysis

Normal values of CSF fluid are as follows:

  • Pressure: 70 - 180 mm H20
  • Appearance: clear, colorless
  • CSF total protein: 15 - 60 mg/100 mL
  • Gamma globulin: 3 - 12% of the total protein
  • CSF glucose: 50 - 80 mg/100 mL (or greater than 2/3 of blood sugar level)
  • CSF cell count: 0 - 5 white blood cells (all mononuclear), and no red blood cells
  • Chloride: 110 - 125 mEq/L

Note: mg/mL = milligrams per milliliter; mEq/L = milliequivalents per liter

Note: Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.

Fluid Appearance

If the CSF looks cloudy, it could mean there is an infection or a build up of white blood cells or protein.

If the CSF looks bloody or red, it may be a sign of bleeding or spinal cord obstruction. If it is brown, orange, or yellow, it may be a sign of increased CSF protein or previous bleeding (more than 3 days ago). Occasionally, there may be blood in the sample that came from the spinal tap itself. This makes it harder to interpret the test results.

CSF Pressure

  • Increased CSF pressure may be due to increased intracranial pressure (pressure within the skull).
  • Decreased CSF pressure may be due to spinal cord tumor, shock, fainting, or diabetic coma.

CSF Protein

  • Increased CSF protein may be due to blood in the CSF, diabetes, polyneuritis, tumor, injury, or any inflammatory or infectious condition.
  • Decreased protein is a sign of rapid CSF production.

CSF Glucose Level

  • Increased CSF glucose is a sign of high blood sugar.
  • Decreased CSF glucose may be due to hypoglycemia (low blood sugar), bacterial or fungal infection (such as meningitis), tuberculosis, or certain other types of meningitis.

Blood Cells in the CSF

  • Increased white blood cells in the CSF may be a sign of meningitis, acute infection, beginning of a chronic illness, tumor, abscess,stroke, or demyelinating disease (such as multiple sclerosis).
  • Red blood cells in the CSF sample may be a sign of bleeding into the spinal fluid or the result of a traumatic lumbar puncture.

Other Results

Increased CSF gamma globulin levels may be due to diseases such as multiple sclerosis, neurosyphilis, or Guillain-Barre syndrome.


Reference: NIH

This information is for general educational uses only. It may not apply to you and your personal medical needs. This information should not be used in place of a visit, call, consultation with or the advice of your physician or health care professional.

Communicate promptly with your physician or other health care professional with any health-related questions or concerns.

Be sure to follow specific instructions given to you by your physician or health care professional.

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