Sorry to bump this thread everyone, but when I just had my spinal tap I felt obligated to explain my situation since reading all these reviews really relaxed my mind and gave me a whole lot of knowledge and put me at ease.

I just had a lumbar puncture (spinal tap) and just want to corraborate what everyone else here said. The process took about 15 minutes (5 for cleaning my back and sterilization, 7 for the spinal fluid to collect and 3 for the local anesthetic/insertion of needle). Its scary to think of a long needle penetrating your body, but the process was relatively painless, (double the pain for a tetanus shot) so not bad at all. The local anesthetic hurt the most, the initial prick and then the release of the anesthetic. For a guy scared of needles and very pain sensitive it is more than manageable. Just a simple wince and deep breath and it was over. Then after waiting, the doctor inserted the needle, it felt like he was just pushing my back. We waited for the CSF to collect then he immediately pulled it out painlessly. The doc and nurse joked about who hurt me most (taking blood or the spinal tap) so that should give you a relative idea of the pain level.

At the end of the day, it was nowwhere near as scary I as thought (granted I'm 5'10, 150lbs). If you are reading this and can feel your spine when you bend your back in the fetal position, you will be fine!! Even if you cant you still should be, but I have no experience on being heavy. Good luck to whoever reads this!

edit: Its been almost 24 hours and no headache. Just a little discomfort at the area and light dizziness if I get up too quickly.