I started having back (flank) pain on both sides today around 2:00. I have taken two rounds of Ibuprofen and use ice packs. This evening, I have experienced flushing, headache, and dizziness. Back is still tender. This did not feel like back strain. I began wondering if it was my kidneys reacting to something. Only difference in my diet today was to open a new package of celery and eat about two stems over several hours. I washed it but it has an odd smell, kind of medicinal, maybe even like herbicide.