How dangerous is a spinal tap for csf fluid? does the spine miss it?

Not dangerous: The most frequent problem might be a post-spinal tap headache when up and about, which can easily be reversed. The missing fluid is typically replenished with a half hour, and usually the puncture closes rapidly. Otherwise, complications a few and far between. It is a very safe process these days.

Thankfully not much: A spinal tap (lumbar puncture) is a procedure designed to examine the cerebrospinal fluid and pressure within the central nervous system. Fortunately the amount of fluid removed will be reproduced within hours. The greatest risk is the development of a headache which occurs in about 10%.

Depends on situation: In experienced hands it is a bit more trouble than a blood draw but not by much. Having a support staff that aids in proper positioning makes it relatively simple. The fluid is not missed. The human body generates about a tablespoon full of spinal fluid every hour which replaces an amount absorbed over the brains surface.The body figures out how much it needs & replaces it.

Not very dangerous : Performed very safely. At times it's performed with the aid of an imaging machine, but ordinarily in a treatment room. The spinal nerves are missed. Ocassionally a person may experience discomfort, paresthesias, nausea and a post spinal tap headache.