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.
Obstruction of flow: If drainage of fluid from a part of your body is blocked, fluid can back up. A blood clot in the deep veins of your leg can cause leg edema. A tumor blocking the flow of blood or another fluid called lymph can cause edema. Critical illness: Burns, life-threatening infections, or other critical illnesses can cause a reaction that allows fluid to leak into tissues almost everywhere.