Definition & Meaning of "lumbar puncture"

What is a "lumbar puncture"?

A lumbar puncture, also known as a spinal tap, is a medical procedure used to collect a sample of cerebrospinal fluid (CSF), which is the clear fluid that surrounds and protects the brain and spinal cord, from the lower part of the spinal column. During the procedure, a needle is inserted into the space between two bones in the lower back to access the CSF. This fluid is then analyzed to diagnose conditions such as infections, bleeding in the brain, multiple sclerosis, or other neurological disorders. Lumbar punctures can also be used to inject medications directly into the CSF.