Tissue edema is an excess of fluid in the intercellular space that causes symptoms of swelling in the body or the whole body. There are many parts of edema. For example, edema in the extremities, especially in both lower extremities, edema in the face, as well as edema in the lungs, edema in the abdomen, and edema in the heart. Usually edema does not occur under normal conditions because the exchange of fluid outside the body and fluid inside the body is balanced. Tissue edema occurs only in the case of disease. Where does edema usually occur? For example, pulmonary edema, pleural edema, ascites caused by liver disease liver disease, or nutritional deficiencies that cause ascites and pleural edema, and heart failure can cause edema of the heart. The fluid of body fluid is not excreted, causing edema of the face, etc.