Edema is swelling caused by excess fluid trapped in the body's tissues (fluid retention). Edema may be generalized or local. Swelling caused by edema commonly occurs in the hands, arms, ankles, legs and feet. It can appear suddenly, but usually develops subtly. You may first gain weight, or wake up with puffy eyes.
Damage to the kidneys can cause decreased levels of protein in your blood. This can contribute to capillary leaking and swelling. The edema associated with kidney disease usually occurs in your legs and around your eyes. Often, patients wait until symptoms are well advanced before seeking medical help.