What is a lumbar puncture?

A lumbar puncture involves inserting a needle into your lower back to reach the fluid around the spinal cord. This can help to diagnose and sometimes treat problems of the brain and spinal cord.

Lumbar puncture is also sometimes called a 'spinal tap'.

Why is a lumbar puncture performed?

A lumbar puncture is done to collect fluid called cerebrospinal fluid (CSF), the fluid that surrounds your brain and spinal cord.

After the procedure, the fluid is sent to a laboratory to help diagnose conditions such as:

• meningitis
• bleeding in the brain
• neurological disorders

It can also help measure the level of pressure in your brain.

To treat certain medical conditions, your doctor may perform a lumbar puncture in order to inject medicine directly into your spinal fluid.

What does a lumbar puncture involve?

You will be asked to lie on your side in a curled-up position (fetal position) or to sit up and lean forward. This position helps your doctor access the space between the bones in your lower back (vertebrae).

Your back will be thoroughly cleaned and local anaesthetic will be injected into your lower back. Once the area is numb, your doctor will insert a thin, hollow needle between two bones in your lower spine. You may feel some pressure as the needle goes in.

A small amount of fluid will be collected. Once the procedure is complete, the needle will be removed. Your doctor will apply pressure to the spot and cover it with a bandage.

How can I prepare to have a lumbar puncture?

Before a lumbar puncture, your doctor will explain the procedure. The explanation will include a discussion of its risks and benefits, so you understand what to expect.

How soon will I recover?

Recovery from a lumbar puncture is usually quick. Most people feel normal again within a few days. You may have mild discomfort or stiffness around the puncture site, which can last for a week or two. You can usually manage this with rest and over-the-counter pain medicines if needed.

To reduce the chance of experiencing a headache, you may be advised to lie down for a few hours after the procedure and to drink plenty of fluids.

There is usually no need to stay in hospital overnight, but it's a good idea to arrange for someone to drive you home.

What complications can happen?

Complications from a lumbar puncture are rare. The most common problem is a headache, which usually goes away within a few hours.

Other possible complications may include:

• bleeding, especially if you are taking a blood-thinning medicine
• infection
• spinal hematoma (a collection of blood in the area where the needle entered)
• cerebral herniation (displacement of part of the brain) — a rare but serious complication

When should I see my doctor?

See your doctor if you have any concerns. Seek urgent medical attention if you experience:

• a worsening headache
• a seizure
• drowsiness or confusion
• fever
• weakness or a change in sensation in your legs

Are there alternatives to a lumbar puncture?

If the traditional method used for a lumbar puncture isn't suitable for you, your doctor may recommend a 'transforaminal' lumbar puncture. This involves placing the needle through a different part of the spine (the foramen). It may be helpful if the usual method isn't possible, for example if you have fused bones, an infection or other issues.

What will happen if I decide not to have the procedure or it is delayed?

Talk with your doctor about what may happen if you choose not to have the procedure or if it is delayed.

Resources and support

• Pathology Tests Explained provides information about spinal fluid examination.
• NSW Government provides information about lumbar puncture.

Learn more about surgical procedures with information, such as:

• Preparing for surgery
• How to find the right health professional
• Medicare

You can also call the healthdirect helpline on 1800 022 222 (known as NURSE-ON-CALL in Victoria). A registered nurse is available 24 hours a day, 7 days a week.