John P. Cunha, DO, FACOEP
John P. Cunha, DO, is a U.S. board-certified Emergency Medicine Physician. Dr. Cunha's educational background includes a BS in Biology from Rutgers, the State University of New Jersey, and a DO from the Kansas City University of Medicine and Biosciences in Kansas City, MO. He completed residency training in Emergency Medicine at Newark Beth Israel Medical Center in Newark, New Jersey.
William C. Shiel Jr., MD, FACP, FACR
Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.
In this Article
- Edema definition and facts
- What is edema?
- What is pitting edema and how does it differ from non-pitting edema?
- What is a pitting edema measurement scale?
- What does pitting edema look like (picture)?
- What causes pitting edema?
- Does salt intake affect edema?
- What causes edema during pregnancy?
- What kind of doctors treat edema?
- Why does a person with heart disease retain fluid?
- Why do people with liver disease develop ascites and edema?
- Why do people with kidney disease have pitting edema?
- What causes pitting edema by heavy loss of protein in the urine?
- What medications treat pitting edema caused by heavy loss of protein in the urine?
- What causes pitting edema in people with impaired kidney (renal) function?
- What is idiopathic edema?
- What is the treatment for idiopathic edema?
- What is the treatment for patients with idiopathic edema who have become dependent on diuretics?
- How does venous insufficiency cause edema?
- Which diuretics are used to treat edema?
- Do people taking diuretics need a diet high in potassium?
- Are diuretics used for other diseases or conditions?
- Find a local Internist in your town
What causes pitting edema?
Edema is caused by either systemic diseases, that is, diseases that affect the various organ systems of the body, or by local conditions involving just the affected extremities. The most common systemic diseases associated with edema involve the heart, liver, and kidneys. In these diseases, edema occurs primarily because of the body's retention of too much salt (sodium chloride). The excess salt causes the body to retain water, which then leaks into the interstitial tissue spaces, where it appears as edema. Medications also can cause pitting edema.
The most common local conditions that cause edema are varicose veins and thrombophlebitis (inflammation of the veins) of the deep veins of the legs. These conditions can cause inadequate pumping of the blood by the veins (venous insufficiency). The resulting increased back-pressure in the veins forces fluid stay in the extremities (especially the ankles and feet). The excess fluid then leaks into the interstitial tissue spaces, causing edema.
Does salt intake affect edema?
The body's balance of salt is usually well-regulated. Most people can consume salt in the diet without concern for developing salt depletion or retention. The intake of salt is determined by dietary patterns and the removal of salt from the body is accomplished by the kidneys. The kidneys have a great capacity to control the amount of salt in the body by changing the amount of salt eliminated (excreted) in the urine. The amount of salt excreted by the kidneys is regulated by hormonal and physical factors that signal whether retention or removal of salt by the kidneys is necessary.
If blood flow to the kidneys is decreased by an underlying condition such as heart failure, the kidneys react by retaining salt. This salt retention occurs because the kidneys perceive the body needs more fluid to compensate for the decreased blood flow. If the patient has a kidney disease that impairs the function of the kidneys, the ability to excrete salt in the urine is limited. In both conditions, the amount of salt in the body increases, which causes the patient to retain water and develop edema.
People with edema experiencing a disturbance in their ability to normally excrete salt may need to either be placed on a diet limited in salt and/or given diuretic medications (water pills). In the past, patients with diseases associated with edema were placed on diets very restricted in salt intake. With the development of new and very potent diuretics, this marked restriction in dietary salt intake is generally less strict. These diuretics work by blocking the reabsorption and retention of salt by the kidneys, thereby increasing the amount of salt and water eliminated in the urine.
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