Common Causes of Leg Swelling or Fluid Overload

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One of the most common medical conditions that many health care providers see on a routine basis is swelling in the legs, also referred to as edema. The routine knee-jerk reaction is the prescription of a diuretic; while this is prescribed for many causes of edema, it is important to understand the main causes of edema so that the right treatment can be prescribed.

Common symptoms of leg edema include shoes that don't fit right and needing bigger size pants. Fluid weight in the legs (as in the body in general) occurs quickly compared to food weight.

High blood pressure is not a direct cause of edema per se, but it may contribute indirectly to edema.

Medication Side Effect

A common cause of edema may be related to one of the medications that you may be taking. Often, it can be seen as a side effect of certain blood pressure medications. Common examples of medications that can cause edema are calcium channel blockers including amlodipine (Norvasc) and nifedipine (Procardia). Other medications can include Minoxidil as well.

Heart Issues, Including Congestive Heart Failure (CHF)

The development of congestive heart failure can be a long-term complication of uncontrolled high blood pressure. Many people with CHF will state that they have increased leg edema in addition to increased shortness of breath. They may experience increased shortness of breath when climbing stairs. They may also be unable to lie flat because of shortness of breath. They often say they needed at least two or three pillows to sleep because of breathing difficulties lying flat.

Liver Issues/Liver Disease

Liver disease can be another cause of increased leg edema. Often there is a hint that a liver condition may be present such as a long history of drinking. Other complications of advanced liver disease can include increased accumulation of fluid in the belly called ascites.

Note that there is a difference between ascites, which is fluid accumulation the peritoneal cavity in the body due to liver disease, and "abdominal swelling." Some people when they experience edema may also say that when they gain "fluid weight" they can have some mild swelling in their belly. Their pants may be a little tighter to button. Some people can accumulate fluid weight in their belly and not in their legs. Everyone is different. This little bit of "belly swelling" is different than the ascites that can occur with liver disease.

Kidney Disease/Kidney Problems

There are many different kinds of kidney disorders. When there is advanced kidney disease, it can be difficult for the kidneys to eliminate the excess sodium and water which can contribute to edema. Another significant health condition that can contribute to the development of edema is the leaking of protein in the urine or proteinuria. One of the most common causes of this is diabetes. The leaking of a lot of protein in the urine can change where some of the body fluid accumulates which can cause edema.

Intestinal Problems/Not Absorbing Nutrients

There are medical conditions called malabsorption syndromes where the intestine is not able to absorb nutrients and minerals. The most common example of this in industrialized nations is actually celiac disease/gluten-sensitive enteropathy. In addition to having an issue absorbing vitamins, nutrients, and certain minerals, there can be an inability to absorb protein as well. This can cause there to be low protein levels in the body; just as in the kidney leaking protein, when there are low protein levels in the body, this can contribute to edema-forming. 

Lymphedema and Venous Insufficiency

These are different but overlapping causes of leg swelling. As we get older, our venous circulation may not function as well as when we are younger. Lymph glands in the leg are responsible for draining fluid from the leg as well. Obesity can be the cause of increased edema because of the above two reasons.

A Word From Verywell

In summary, it is important if you have edema, the possible cause(s) be evaluated. Often there is more than one cause present. Many people have a combination of contributing factors that lead to the development of edema. For example, one person may have a history of CHF and obesity as well as be on a medication that can cause edema in addition to having some venous insufficiency.

The evaluation and management of edema should be personalized and the first step is recognizing the possible causes that can contribute to its development.

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