I was really ill last week, temp went to 40.3, couldn't move etc. etc. for a few days, it eased but now a week later it's starting again. Temp is lower (39 something) , can obviously move (couldn't 'til now though) but my back is so so sore. It feels like someone has smashed my spine with a hammer. Everytime I google flu not much is mentioned about a sore back - could it be something else, esp. as it's come back?