I just had my second one in a month. I went in for same day surgery (outpatient). They put an iv in and the doctor explained what he was going to do. They then gave me versed which knocked me out. According to where you tell them you are hurting and what sensations you are experiencing and where you experience them, they will inject a cortizone/numbing med into your spine. For the next 8-12 hours your back and legs will feel great!!! (until the numbing meds wear off) in my experience, for the next 2 days you will hurt worse, and then by the 3rd day, you feel 16 years old again! Unfortunately, some people, like me, have to have them repeated in about 3 weeks if the first doesn't take well. My first took well, but in about a week, I could tell that my pain was coming back in all of the familiar places. It has been a week since my second one, and the pain is better, but by the end of the afternoon, I can tell that I need to get off my feet or take some meds. Hope this helps! Jenn