What you can expect

By Mayo Clinic Staff

Lumbar puncture is usually done in an outpatient facility or a hospital. You're asked to change into a hospital gown.

Then you lie on your side with your knees drawn up to your chest, or you sit and lean forward on a stable surface. These positions flex your back, widening the spaces between your vertebrae and making it easier for your doctor to insert the needle.

Your back is washed with antiseptic soap or iodine and covered with a sterile sheet.

During the procedure

  • A local anesthetic is injected into your lower back to numb the puncture site before the needle is inserted. The local anesthetic will sting briefly as it's injected.
  • A thin, hollow needle is inserted between the two lower vertebrae (lumbar region), through the spinal membrane (dura) and into the spinal canal. You may feel pressure in your back during this part of the procedure.
  • Once the needle is in place, you may be asked to change your position slightly.
  • The cerebrospinal fluid pressure is measured, a small amount of fluid is withdrawn, and the pressure is measured again. If needed, a drug or substance is injected.
  • The needle is removed, and the puncture site is covered with a bandage.

The procedure usually lasts about 45 minutes. Your doctor may suggest lying down after the procedure.

After the procedure

  • Plan to rest. Don't participate in strenuous activities the day of your procedure. You may return to work if your job doesn't require you to be physically active. Discuss your activities with your doctor if you have questions.
  • Take a pain medication. A nonprescription pain-relieving medication that contains acetaminophen can help reduce headache or back pain.
Dec. 06, 2014