Lumbar puncture, also called a spinal tap, is a procedure in which the spinal fluid surrounding the spinal cord is withdrawn through a needle placed in the lumbar spine (or lower back) and examined in a laboratory.   The procedure will be performed by a physician trained in the use of X-ray equipment, called fluoroscopic equipment, which allows the doctor to view the needle as it is placed into the spinal canal.   



  • Preregister at the hospital.

  • A nurse from the hospital will call you to discuss the procedure.

  • You must make arrangements for someone who is 21 y/o or older to drive you to and from the test.

  • DO NOT take aspirin, dipyridamole, clopidogrel, warfarin, apixaban, rivaroxaban, or dabigatran within 7 days prior to the test. These medications are often referred to as “blood thinners”.

  • DO continue to take all of your other medications as prescribed by your physicians.

  • DO NOT consume any alcohol for at least 24 hours prior to the test.

  • DO take your usual dose of insulin and eat a light meal at least two hours before the procedure.

  • DO NOT eat or drink anything two hours before the procedure. 

  • Bring an updated list of your current medications and allergies to the hospital.

  • Bring your identification card and all insurance cards to the hospital.

  • DO NOT bring valuables to the hospital, e.g., jewelry, electronic devices, etc.



  • Report to the hospital on time.

  • Tell the staff immediately if you are pregnant or think you may be pregnant.

  • During the procedure, the radiologist and technologist will be in the room with you.

  • You will wear a hospital gown during the examination.

  • You will either lie on your side with your knees drawn as close to your chest as possible and your chin toward your chest; or lie on your stomach with a small pillow beneath your lower abdomen.

  • Your back will be cleaned with an antiseptic and sterile drapes will be placed around the area.

  • A local anesthetic will be injected into the area on your back. You may feel a slight burning sensation.

  • A hollow needle is inserted in the lower back. This sometimes causes a sensation of pressure in the lower back.

  • The spinal canal is penetrated and fluid is collected. The spinal cord is not touched by the needle.

  • The needle is removed after the fluid is obtained. The area will be cleaned and covered with a small bandage.

  • You may be instructed to lie on your back or stomach for about an hour in Radiology Recovery.

  • A blood sample will be taken from your arm and tested, along with the spinal fluid, in the laboratory.

  • Before discharge, the Radiology nurse will go over written postop instructions.  Please follow these at home.



  • DO NOT drive for 12 hours after the test. 

  • Remain flat on your back as much as possible for 24 hours after the test.

  • Drink at least 2 ½ quarts (10 cups) of fluids in the first 24 hours after the test.

  • If you were taking blood thinners prior to the test, start taking them again.

  • Notify the Radiology Department if you experience any drainage from the puncture site, fever, stiff neck or headache not resolved by lying down.

  • Post LP headache or “spinal headache” is a headache which occurs when sitting or standing after a lumbar puncture.  This type of headache is caused by leaking of spinal fluid into the soft tissues of the lower back.  It always resolves after lying down.  If you develop a spinal headache, lay down for several more hours and drink more fluid.  If you are unable to stand due to spinal headache at 48-72 hours after the lumbar puncture, please notify CNS and you will be referred to an anesthesiologist for a “blood patch”.  In this procedure, some blood is drawn from your arm and injected into the tissues at the lumbar puncture site to act as a pressure dressing in order to stop the spinal fluid leak.   

  • If you do not have a spinal headache, you can resume normal activities in 24 hours. 

  • The test results will be sent to the CNS doctor who will discuss the results at your follow up visit.