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Back Pain Health Center

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Lumbar Puncture


For a lumbar puncture, you lie on your side with your knees drawn up toward your chest. This position helps widen the spaces between the bones of the lower spine so that the needle can be inserted more easily. A numbing medicine (local anesthetic) is put in the skin. Then a long, thin needle is put in the spinal canal to collect a sample of cerebrospinal fluid (CSF). Your doctor may need to move to another area of your spine if it is hard to get to the spinal fluid.

The color, blood cell counts, and amounts of protein, glucose, and other substances are measured in the CSF sample. Some of the sample may be put into a special culture cup to see if any bacteria or fungi grow. The pressure of the CSF also is measured during the procedure.

ByHealthwise Staff
Primary Medical ReviewerE. Gregory Thompson, MD - Internal Medicine
Specialist Medical ReviewerJoseph O'Donnell, MD - Hematology, Oncology

Current as ofSeptember 9, 2014

WebMD Medical Reference from Healthwise

Last Updated: September 09, 2014
This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.

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