Edema

Edema refers to excessive fluid accumulation in the interstitial space outside the blood vessels, which is one of the common clinical symptoms. About 5% of the human body's body fluids remain in the interstitial spaces and shuttle between the various nucleus and capillaries of the body. Edema is manifested as a noticeable depression when a finger presses a part with less subcutaneous tissue (such as the front side of the calf). Chinese medicine calls it "water gas", also known as "edema". Edema is a common pathological process. The accumulated body fluid comes from plasma, and the ratio of sodium to water is about the same as plasma. Traditionally, the accumulation of excessive body fluids in the body cavity is called hydrops or fluid, such as pleural effusion, peritoneal effusion, and pericardial effusion.