What Are Abdominal Pain With Swollen And Distended Upper Abdomen Suggestive Of?

Recently my stomach seems to have enlarged a good deal because none of my pants fit. Also, I have had some discomfort on the left side upper abdomen for weeks now but just noticed it getting worse over the past several days. Then just 5 minutes ago I felt the area and looked in the mirror and there is a large area upper left abdomen that is swollen or is a lump, but it s large, like 6 inches wide and a few inches tall, just below my breast but not part of my breast and seemingly under or on top of the left rib cage. It s noticeable and cramping constantly now. I am not constipated nor does it feel anything like that. And when I bend or stoop forward the pain is much worse. The pain also seems to extend around that entire area like through my rib cage or something it s hard to explain. Any ideas? I forgot to mention that I have been having swelling in the left foot, ankle, lower leg and knee, only the left side and my knee is painful and difficult to raise it and difficulty walking.