Edema

Edema is the accumulation of fluid in tissues, mostly in interstitial spaces. Fluid enters the tissues from blood vessels due to increased blood pressure, capillary wall permeability, and disturbances in the activity of glands regulating water metabolism (pituitary, thyroid, adrenal glands). As the tissues swell, their volume increases, shape changes, their skin becomes stretched, pale, shiny, and cold. When such tissues are pressed, a pit remains. When edema occurs, the accumulated fluid compresses the swollen tissue cells and disrupts the function of these and adjacent tissues. The immune reactivity of swollen tissues decreases, making them more prone to inflammation. When the cause of edema resolves, fluid is reabsorbed from the tissues. If edema persists for a long time, tissues become non-elastic, and even after removing the cause of edema, fluid may not be absorbed for a long time.

Source | Author Doctor Nikas Samuolis, reviewed by Prof. Virginijus Šapoka | Vilnius University | Faculty of Medicine | Head of the Department of Internal Medicine, Family Medicine, and Oncology