For several months the night I am feeling discomfort, pain, tightness discomfort right side under ribs  when I was lying on my right side. When I sleep on the left side or or back I do not feel anything. Discomfort or minor pain and feel well when I work hard physically work. During the day I do not feel or feel very little discomfort. Doctor performs USG, for liver, kidneys and pancreas. But found none. Blood tests and urine also nothing to show