Kids Health Info

Lumbar puncture

  • A lumbar puncture is a test where a doctor uses a needle to get fluid from your child's lower back. This fluid is called cerebrospinal fluid, or CSF. Your child lies on their side and is held still, with their knees tucked into their chest and head bent forward.  Babies will be curled in a ball to get a better position. A doctor puts a needle between the bones of the lower back. It does not go near the spinal cord. Lumbar punctures are also sometimes called a spinal tap or LP.

    When is it needed?

    A lumbar puncture is needed to test the fluid around the brain and spinal cord. This test is done to find out if a child has meningitis (a serious infection around the brain). Meningitis may be suspected in a baby with a fever, especially in babies less than one month old. If this is the case, it is important for your child to have the lumbar puncture as it is the only way to know for sure if they have meningitis. Early diagnosis of meningitis can greatly improve long-term outcomes. If your child has meningitis, they will need other tests and treatment in hospital. 

    Lumbar punctures are also done for other reasons, including to measure pressure and look for chemicals that may affect brain function.

    What to expect

    Your child lies on their side with their knees tucked into their chest or curled up in a ball. Young children will be held in this position by an assistant. A doctor puts a needle into the spaces between the lumbar vertebral spine to the area where the fluid is.  This area is called the subarachnoid space.

    lumbar puncture


    Does it hurt?

    It is an uncomfortable and sometimes painful test. Your child will be held still, and babies and small children do not like this and will often cry. We can help to numb the skin with some cream or with an injection. We may be able to give your child some medicine to make them feel calmer and less scared.

    What are the risks?

    Lumbar puncture is a very safe test. Sometimes we are not able to get fluid and may have to try more than once. A small number of children may have a headache or backache for a day or two after the test. The risk of any serious complications, including bleeding, infection or damage to nerves, is extremely small.

    Care after the procedure

    Your child can be bathed normally. If there is a band-aid or dressing on your child's back it can be taken off the next day or left to fall off by itself if your child prefers. If they have a headache or sore back they can have some paracetamol (e.g. Panadol).

    Key points to remember

    • Lumbar puncture is the only way to be sure if your child has meningitis or not.
    • It is a very safe test.

    More information


    Developed by The Royal Children's Hospital General Medicine and Emergency Medicine. First published: Dec 2003. Reviewed: May 2011

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