Beth
I've had six of these blocks, and they're nothing to be nervous about. They give you a local anaesthetic to numb the spot where they'll do the block, then you're given a shot of an anti-inflammatory drug plus an anaeathetic into the area of your back where they think the pain is originating. It only takes about 15 minutes. You'll feel some numbness in your leg for about 4-8 hours, so you have to have someone help you at home till you're able to walk safely. If you're lucky, your pain will be lessened for a period of time from days to weeks or longer. For me, I only got short-term relief (a few days), but my pain has been severe, so it might take more blocks for me.