I've had spinal injections before but this time I got a major headache and pain radiates down my right side. I've had 2 spinal fusions on the lower part of my back. My question is why didn't the pain stay gone? I know it takes a few days to kick in fully. The only other time I've had a headache like this painful was when spinal fluid was taken. Ice nor heat helps with the pain at the sight of my injections. Can someone please help me.