Hi,
How are you?
It is a very unusual case as all your tests are normal and still you have swelling in the body. It is hard for me to give a straightforward answer.
Some causes of swelling in the legs, feet and stomach are heart failure, kidney failure, varicose veins, insect bite or stings, food allergies, and abdominal cancer.
What all tests did you under go?
Have all these possibilities been excluded? Please elaborate.