What's a Spinal Tap (Lumbar Puncture)? (Video)

What's a Spinal Tap (Lumbar Puncture)?

A lumbar puncture, or spinal tap, is a medical test that involves collecting a small sample of cerebrospinal fluid (CSF) for examination. This clear, colorless liquid helps "cushion" the brain and spinal cord, or central nervous system.

Doctors use the fluid sample to look for signs of possible infections or other illnesses.