What Causes Tightness And Discomfort In The Stomach, Chest And Throat?

I don t know how to help my mother, who is 83 but has been until past year feeling good and active. She s been complaining of fullness, tightness from stomach, into chest, some in back, now throat that makes her so uncomfortable, she cries daily. After several times in hospital lately past month, she s still the same. The last time, she was in for a bladder biopsy, then found 16 pounds of fluid on chest, and she s taking a medicine for that. But no other diagnosis or treatment for this presenting problem, which is persisting. They had her in hospital for one week for chest pain , but found nothing to do for her; it was the couple weeks later when she was in for bladder biopsy that they found the fluid on her chest through another test, thanks to anesthesiologist. So it seems for this presenting issue, nothing found. She does have hx of afib, stent, pacemaker, constipation, kidney cancer, bladder cancer, lung cancer (all cancers fine after surgery...left with one kidney, one lung), and is also on blood pressure medicine. I wonder if they keep looking at heart possible issues, and might be missing something in stomach or abdomen. She says she always feel so much fullness from stomach up, that can t feel like eating. And with such chronic constipation and days without BM often, though says she can pass gas, I wonder if its that source. It s not a sharp pain, but uncomfortable to extent it makes her cry all the time and not moving around much. She does get out of breath easily with only 10 steps. Anything you can suggest for me so I can get her some help? Thank you, Valerie