What Causes Pain In Ribs And Upper Abdomen?

I m 53 years old, 5 11 , about 250 lbs. My work involves fairly frequent heavy lifting and carrying. I have had daily upper right side back & rib pain for 3-4 months now that sometimes radiates around to the upper right abdomen. It is not excruciating, just very annoying. It goes away completely at night after work when I can sit in a comfortable chair or when I lie down to go to sleep. Some days when it is worse it will hurt for an hour or so when I first lie down but is always gone in the morning. It usually returns by mid morning and gets a little worse through the day unless I have a pretty non physical day then I may hardly notice it all day. I ve had a couple of people, my wife for one, say they can feel a very noticeable difference in the area that hurts and the other side of my back. The side that hurts feels hard and tight is what they said. I had similar symptoms 2 - 3 years ago and thought it may be gallbladder but a sonogram showed nothing. Also had a CT scan to check something else and the report mentioned arthritis in the thoracic area of my spine. I may be borderline hypochondriac, I just want to make sure its muscle or bone related and not a tumor or something.