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.
The higher pressure causes swelling in the legs and feet. Congestive heart failure, a condition in which the heart can no longer pump efficiently, causes fluid buildup in the lungs and other parts of the body. Swelling is often most visible in the feet and ankles. Pregnancy can cause edema in the legs as the uterus puts pressure on the vena cava, a major blood vessel that returns blood to the heart from the legs. Fluid retention during pregnancy also can be caused by a more serious condition called preeclampsia.
Swollen Ankles. Swollen feet and legs, referred to medically as edema, occur when fluid is retained in the spaces between body cells. Edema typically affects the feet, ankles and lower legs, but can also impact any area of the body, causing systemic symptoms. Initially, the feet and legs will appear swollen as the day progresses, but after a period of time, the swelling will set in first thing in the morning and continue to worsen throughout the day.