I felt the coldness of the alcohol or I guess it was a betadyne wipe used to cleanse the area first. After that, I remember the nurse practitioner saying, ‘Here’s a little pinch’, when giving the local anesthesia to numb the area. But since it was still cold back there from the evaporating cleansing fluid, I didn’t feel the pinch at all.

There wasn’t any pain or discomfort during the test. I was aware of something being done back there, but since it was out of my view and numb it was really a non-event. Like I said, the nurse practitioner who did the procedure and her assistant were both carrying on a conversation with me the entire time.
The fluid itself is clear and the little tubs that the technician fills are sent to the lab for testing.

Here’s a list of test results that can be found with a lumbar puncture:
Serious bacterial, fungal and viral infections, including meningitis, encephalitis and syphilis
Bleeding around the brain (subarachnoid hemorrhage)
Certain cancers involving the brain or spinal cord
Certain inflammatory conditions of the nervous system, such as multiple sclerosis and Guillain-Barre syndrome
Autoimmune neurological conditions
Alzheimer’s disease and other forms of dementia

Obviously not all of these apply to you but you can see why your doctor wants to have the test run. It’s a good way to narrow down an potential issues you might be having.