Numerous diseases can cause ankle swelling. According to the U.S. National Library of Medicine and the National Institutes of Health (NIH), foot and ankle swelling is a common health complaint, especially among older individuals. The accumulation of fluid in the legs, ankles and feet is known as peripheral edema. The NIH notes that swelling in the lower extremities--which typically is painless--is particularly noticeable due to the effects of gravity.
Congestive Heart Failure
Congestive heart failure can cause ankle swelling. According to the American Heart Association (AHA), congestive heart failure occurs when a person's heart is unable to pump sufficient blood to his tissues and organs. Congestive heart failure can be caused by the following: coronary artery disease or narrowed arteries that supply blood to the heart, a previous heart attack, hypertension or elevated blood pressure, heart valve disease, heart muscle disease, congenital heart defects and heart valve infection. The AHA notes that as a person's cardiac output or blood flow out of the heart decreases, the amount of blood coming back to the heart decreases, causing more blood to remain in the veins, which results in tissue congestion and swelling or edema. According to the AHA, congestive heart failure-related swelling is most common in the legs and ankles, although fluid can also accumulate in a person's lungs and cause breathing difficulties.
Preeclampsia
Expectant mothers may experience ankle swelling caused by preeclampsia. The Preeclampsia Foundation states that preeclampsia is a pregnancy- and postpartum-related condition affecting both the mother and the unborn child and that it affects about 5 to 8 percent of pregnancies. A progressive condition, preeclampsia is characterized by elevated blood pressure, protein in the urine, sudden weight gain, headaches, vision changes and swelling in the ankles. According to the Preeclampsia Foundation, preeclampsia typically occurs in the second or third trimester of a pregnancy and is closely associated with two other problematic health conditions: pregnancy-induced hypertension (PIH) and toxemia--the presence of toxic substances in the bloodstream. The Preeclampsia Foundation states that preeclampsia, along with pregnancy-related hypertension disorders, is one of the most common causes of death in mothers and infants, causing 76,000 maternal deaths and 500,000 infant deaths annually, as of July 2008.
Kidney Failure
Kidney failure is another disease that can lead to ankle swelling. According to the National Institute of Diabetes and Digestive and Kidney Diseases or NIDDK--a division of the National Institutes of Health--a person's kidneys remove excess fluid, minerals and waste from her blood, and they produce hormones that keep her bones strong and her blood healthy. There are two types of kidney failure--acute and chronic--which are caused by different factors. When a person's kidneys fail, metabolic waste products accumulate in her body, her blood pressure may rise, her body may retain water and her red blood cell production may decrease. The NIH notes that the following are common symptoms associated with kidney failure: anorexia or decreased appetite, fatigue, nausea or vomiting lasting for days, prolonged bleeding, slow or sluggish movements, and swelling of the legs, ankles and feet, among others.
