Edema and swelling are two terms to describe the same thing. It results from inflammation of tissues that have been damaged and increased blood circulation in the area
Immediately after an injury, the body floods the injured area with white blood cells and other cells to destroy bacteria and eat up dead or dying cells so that the repair process can begin. Swelling or edema, results from this flood of infection fighters. Normally, a system of vessels similar to arteries and veins called lymphatic vessels, drain the area of excess fluid and cells, but after an injury the lymphatics get blocked. The excess fluid and cells collect in the spaces between the tissues around the site of the injury. As more and more fluid and cells try to occupy a limited amount of space, they start to press on the surrounding tissues and this pressure is perceived as pain.
Generally, anything that ends in “ítis” means inflammation. Classic signs of inflammation include redness, heat, swelling, and pain. For example: tendonitis (tendon inflammation), bursitis (bursa inflammation), arthritis (joint inflammation), etc. Even though these structures are different, they all swell in similar ways. Consequently, they can all be treated in similar ways.