About the data: We used the family income data from the 2013 American Community Survey. This counts only families, which the government defines as households with two or more people related by birth, marriage or adoption. The graph focuses on families living in the country's 30 most populous cities.
Diseases and conditions that may cause edema include: 1  Congestive heart failure. 2  Cirrhosis. 3  Kidney disease.  Kidney 1  damage. Weakness or damage to veins in your legs.  Inadequate lymphatic 1  system. Symptoms.  Risk factors.
Swelling of the feet, ankles, and legs is called edema. It is caused by excess fluid that has collected in the tissues. Extra fluid in the body settles in the lowest part because of gravity.