November 28, 2015
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Lumbar Puncture (cont.)

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What is normal CSF?

Normal values for spinal fluid examination are as follows:

  • Protein (15-45 mg/dl)
  • Glucose (50-75 mg/dl)
  • Cell count (0-5 mononuclear cells)
  • Initial pressure (70-180 mm)

These normal values can be altered by injury or disease of the brain, spinal cord, or adjacent tissues. The values are routinely evaluated during examination of the spinal fluid obtained from the lumbar puncture. Additionally, spinal fluid is tested for infection in the microbiology laboratory.

A health-care provider will usually review and interpret the test results with the patient. These results often will need to be evaluated in relation to other blood and radiologic test results.

What diseases are diagnosed by examination of the CSF?

Spinal fluid obtained from the lumbar puncture can be used to diagnose many important diseases such as bleeding around the brain; increased pressure from hydrocephalus; inflammation of the brain, spinal cord, or adjacent tissues (encephalitis, meningitis); tumors of the brain or spinal cord, etc. Sometimes spinal fluid can indicate diseases of the immune system, such as multiple sclerosis.

What are possible risks, complications, or side effects of a lumbar puncture?

When spinal fluid is removed during an LP, the risks include headache, brain herniation, bleeding, and infection. Each of these complications are uncommon with the exception of headache, which can appear from hours to up to a day after a lumbar puncture. Up to 25 % of patients will get headaches after the procedure. Headaches occur less frequently when the patient remains lying flat several hours after the procedure.

What are the benefits of a lumbar puncture?

The benefits of the LP depend upon the exact situation for which it is performed, but a lumbar puncture can provide lifesaving information.


Longo, D.L., et al. Harrison's Principles of Internal Medicine, 18th ed. New York: McGraw-Hill Professional, 2011.

Medically Reviewed by a Doctor on 11/2/2015


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