i have tenderness on the outside of my right rib cage. It started a few weeks ago.. I sleep on my right side and where my mattress touches my ribs is sore. The tenderness has moved down several dermatomes, so now it runs from about the 8th rib down to below the 12th rib, and the vein there is bulging a little. could this be herpes sine zoster? What could this be? no abdominal pain, so it's not gallbladder, I don't drink so doubt it's anything liver related. It has been going on too long to be a pulled muscle, I think.