What causes the pain and swelling on right side of abdoman?

You should have blood testing done by the doctor. This would show

if this may be the liver/gallbladder/biliary problem.

The liver is located in the upper right hand quadrant of the abdomen,

up under the rib cage. If it develops inflammation, it can enlarge

in size and cause a tight full feeling on this side. However, the

gallbladder is located right under the liver and can cause pain

that can come/go or remain constant if a gallstone moves into

the ducts from the gallbladder...or if there is a growth, infection,

or even malformation of the duct...or anything that cause a

blockage there.

It is best not to let this go. If this is a liver or biliary problem...

getting treatment could reverse the problem because it

develops into something more serious. Best wishes