I have a painful throbbing headache;it s painful to sit up, to shift positions, to walk, etc. I was just in the ER yesterday for a kidney infection . Right kidney is inflamed, thought it was appendix. Just before I left is when the headache started. I noticed later on that the back of my neck at the base of my skull was super sore, as well as the sides. Im not sure what could be causing this, I did get an antibiotic dose through an Iv yesterday. I don t think the Iv was all the way in the vein .. Don t know if that could be the cause. I have been sick & running a fever the last 3 days. My boyfriend complained about a headache & a tender neck also.