Peripheral edema, commonly referred to as swelling of the ankles and feet, is the result of an abnormal accumulation of fluids in the lower extremities. Prolonged standing or sitting, excessive salt intake, certain medications as well as underlying medical conditions such as heart or kidney failure can result in swelling of the feet and ankles.
Rheumatoid Arthritis
Rheumatoid arthritis is an autoimmune disorder believed to be caused by auto-reactive B lymphocytes. The immune system mistakes the tissues of the joints as foreign antigens resulting in the production of CD20 positive B antibodies. These CD20 positive B cells cause an inflammation in the joints of the body by the release of pro-inflammatory cytokines that promote joint destruction. Rheumatoid arthritis is characterized by the symmetric inflammation of the joints of the hands, shoulders, wrist, hips, ankles and elbows. The pro-inflammatory cytokines result in an accumulation of fluids in the joints of the feet, ankle, wrists and hands. According to the American Academy of Orthopaedic Surgeons, 90 percent of rheumatoid arthritis patients develop swelling in the ankles and feet.
Nephrotic Syndrome
Nephrotic syndrome is a medical condition characterized by damage to the kidney, primarily the cluster of glomeruli blood vessels in the basement membrane of the kidneys. The glomeruli function as the kidney's primary filtration capillary, filtering waste products and excess water from the blood. In nephrotic syndrome, damage to the glomeruli blood vessels impairs the kidney's ability to retain blood protein, primarily albumin, which is necessary to maintain the volume of fluid in the body. Proteins such as albumin leak out of the blood into the intestitial space and excess amounts are excreted in the urine. According to MayoClinic.com, symptoms commonly associated with nephrotic syndrome include swelling of the face, ankles and feet.
Emphysema
Emphysema is a medical condition characterized by the progressive destruction of the alveoli air sacs and surrounding lung tissues. Smoking is the leading cause of emphysema leading to an inflammation of air sacs in the lungs. The inflammation and destruction of alveoli air sacs and surrounding lung tissue causes an accumulation of fluid in the lungs. In emphysema, the lungs are unable to shrink upon exhalation as a result of reduced elasticity. This causes air to become trapped in the alveoli sacs leading to blood deoxygenation. This results in the characteristic wheezing and shortness of breath seen in emphysema. Symptoms also common in emphysema are excess production of mucus and swelling in the ankles and feet.
