When I'm Driving Or Just Setting Up Something Feels Like

When I'm driving or just setting up something feels like it's swollen on my lower left side of the back. When I'm sitting in a seat, I can feel something swollen. I do have L4, and L5 lower vertebra degenerated disk. Is this a factor of what I'm experiencing?
I recently went to the E.R. and they checked me out said everything was fine.
At first, I thought it was a kidney problem but through testing, everything was negative. They even took a scope into my privacy area and my bladder, everything checked out OK?