A lumbar puncture collects a small sample of the cerebrospinal fluid, the clear liquid that surrounds the brain and spinal cord. It helps diagnose infections such as meningitis, bleeding around the brain, inflammatory conditions such as multiple sclerosis and some nerve disorders. It can also measure the pressure of the fluid.

At Apex, the neurologist first explains why the test is needed and reviews medicines, especially blood thinners, and any bleeding problems. A brain scan may be advised beforehand if there is a concern about raised pressure in the skull. The patient lies on their side, curled up, or sits leaning forward. The lower back is cleaned and numbed, and a thin needle is passed between two vertebrae into the fluid space. A few millilitres are collected, which takes a few minutes.

Patients are usually asked to lie flat for a period afterwards, and drinking fluids is encouraged. The sample is sent to the laboratory, and results are discussed once they are ready.

How the Procedure Can Help

The fluid can show infection, inflammation or bleeding that blood tests and scans may miss. It can allow early diagnosis and treatment in urgent conditions such as meningitis.

Risks and Considerations

A headache after the procedure is the most common problem and often improves with rest and fluids. Back pain, bleeding, infection and, rarely, nerve irritation can occur. Severe headache, fever, leg weakness, numbness or difficulty passing urine afterwards needs urgent review.