Spinal Tap (Lumbar Puncture)
Overview
What is a spinal tap (lumbar puncture)?
To perform a spinal tap (also called a lumbar puncture), your healthcare provider inserts a needle into your lower back to get a sample of cerebrospinal fluid. Cerebrospinal fluid is the clear liquid that surrounds your spine and brain. A lab tests the fluid sample to check:
- Presence of bacteria, fungi or abnormal cells.
- Glucose (blood sugar) levels.
- Protein types and levels.
- White blood cell types and levels.
Why do healthcare providers perform spinal taps (lumbar punctures)?
Your healthcare provider may perform a spinal tap to test for:
- Bleeding in the brain (intracranial hemorrhage).
- Dementia.
- Leukemia or other cancers.
- Meningitis and encephalitis (brain and spinal cord infections).
- Multiple sclerosis or other autoimmune disorders.
- Myelitis (spinal cord inflammation).
- Excess cerebrospinal fluid.
Healthcare providers also use spinal taps to:
- Administer regional anesthesia, such as an epidural to block pain in the lower part of the body.
- Inject dye for an X-ray diagnostic test (myelogram).
- Inject cancer medications or muscle relaxers.
- Relieve intracranial (head) pressure.
Test Details
How should I prepare for a spinal tap (lumbar puncture)?
You may get a blood test before the procedure to ensure that your blood clots normally. You should follow your healthcare provider’s instructions on what to do before the procedure. Generally, you need to:
- Provide a current list of medications and supplements.
- Stop taking blood-thinning medications, such as aspirin and warfarin.
- Tell your doctor if you’re allergic to povidone-iodine (an antiseptic) or procaine (an anesthetic).
How is a spinal tap (lumbar puncture) performed?
Depending on your situation, a spinal tap may take place as an outpatient procedure (you go home the same day) or in the hospital. If you have an outpatient procedure, someone needs to drive you home afterward. The procedure takes 15 to 30 minutes.
For the procedure, your provider may have you lie on your left side with your knees pulled up to your chin (fetal position). Or you may sit and lean forward with your arms and head resting on a table.
During a spinal tap, your provider:
- Cleans your skin with an antiseptic.
- Injects a local anesthetic into your lower back to numb the area. You might feel a slight burning sensation.
- Inserts a thin, hollow needle between two vertebrae (spinal bones) in the lower part of the spine. You may feel some pressure.
- Draws fluid into the needle or injects medication or dye.
- Gently withdraws the needle.
- Cleans the skin again with an antiseptic and covers the puncture site with a bandage.
What should I expect after a spinal tap (lumbar puncture)?
After your provider finishes the procedure, you’ll need to stay in this fetal position (or lie down if you were seated) for at least one hour. You should get plenty of rest and fluids afterward. With your provider’s OK, you may be able to return to work. But you should avoid strenuous exercise or activities for 24 to 48 hours.
What are the potential risks or complications of a spinal tap (lumbar puncture)?
Spinal tap complications, such as infections and bleeding, are rare. There’s no risk of spinal cord damage. The cord sits higher than the area of the lumbar spine area where the spinal tap takes place.
About 10% of people who get a spinal tap develop a spinal headache (intense pain when sitting or standing). This headache may come on within hours or several days after the procedure. The pain typically goes away on its own in a couple of days, but it may linger for a week or more. Along with the spinal headache, you may experience:
- Fast heart rate (tachycardia).
- Low blood pressure (hypotension).
- Nausea.
Results and Follow-Up
When should I get my test results?
The timing of spinal tap results depends on the reason you had the test. If you need an emergency spinal tap to check for life-threatening conditions like a brain bleed or meningitis, lab results will come quickly. Otherwise, your provider should get results within a week.
When should I call the doctor?
Spinal headaches typically go away in a few days. Over-the-counter pain medicines, staying hydrated, and drinking caffeinated beverage scan help. You should call your healthcare provider if the headache is extremely painful and lasts more than a few days, or you experience:
- Bloody discharge or drainage at the puncture site.
- Signs of infection, such as fever.
A note from Cleveland Clinic
A procedure that involves the spine may sound scary, but spinal taps carry little risk. Talk to your healthcare provider about any concerns. If you develop a spinal headache after the procedure, your provider can offer suggestions to ease the pain.
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