(Cerebrospinal Fluid Analysis; Cerebrospinal Fluid Tap; Spinal Tap)
by Editorial Staff and Contributors
A lumbar puncture is a test of the fluid around your spine and brain. This fluid is called cerebrospinal fluid (CSF). It provides protection and nutrition to the brain and nerve cells. CSF also helps to remove waste products from the brain.
Reasons for Procedure TOP
The test is done to look for abnormalities in the spinal fluid. It may be done to help diagnose conditions such as:
The procedure may also be done to:
Possible Complications TOP
Problems from the procedure are rare, but all procedures have some risk. Your doctor will review potential problems, like:
What to Expect TOP
Prior to Procedure
Just before the procedure, your doctor will clean the site where the needle will be inserted.
Local anesthesia will be used most often. It numbs just a small area. The medication is injected with a needle.
Description of Procedure TOP
You will lie on your side with your knees drawn up in front. Some punctures may be done while you sit on the edge of the bed. A needle will be inserted into the spinal canal through the lower back. A sample of CSF will be taken through the needle.
During the procedure, the pressure of the CSF may be noted. If you have discomfort, the needle may need to be repositioned. It may take several minutes to collect the fluid needed. The needle will be removed. A dressing will be placed over the puncture.
Immediately After Procedure TOP
You will lie down for 10-15 minutes. In most cases, you will be able to go home after the procedure. If you have a severe headache or need immediate treatment, you may need to stay longer.
How Long Will It Take? TOP
About 30-45 minutes from setup to completion
Will It Hurt? TOP
Discomfort is minimal to moderate. The anesthetic will sting when first injected.
Post-procedure Care TOP
When you return home after the procedure, do the following to help ensure a smooth recovery:
Call Your Doctor TOP
After arriving home, contact your doctor if any of the following occurs:
If you think you have an emergency, call for medical help right away.
Family Doctor—American Academy of Family Physicians
National Institute of Neurological Disorders and Stroke
About Kids Health—The Hospital For Sick Children
Lumbar puncture (LP). EBSCO DynaMed website. Available at
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Updated May 31, 2012. Accessed February 13, 2014.
Torpy J, Lynm C, et al. Lumbar puncture. JAMA. 2006;296(16):2050.
Lumbar puncture test. The University of Iowa website. Available at:
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Accessed February 13, 2014.
Last reviewed January 2015 by Rimas Lukas, MD
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