Common causes of edema (swelling)

Edema (commonly referred to as “swelling”) occurs when fluid becomes trapped in soft tissue throughout the body. Because of gravity, edema is often found in the legs, ankles, and feet. Here are conditions that are likely to cause this condition.

Heart failure

Heart failure affects more than 5 million people in the U.S., and it’s the leading cause of hospitalizations in people over 65. Risk factors for developing heart failure include advanced age, obesity, diabetes, hypertension, smoking, congenital heart defects and heart attacks.

Heart failure occurs when the heart is not able to contract as strongly as it needs to pump blood throughout the body. When the heart loses its ability to pump effectively, fluid backs up into the lungs, and then into the lower extremities.

Patients with heart failure can experience shortness of breath, fatigue, palpitations, wheezing, nausea, weight gain, chest pain and edema in their lower extremities.

Heart failure is often managed with medications that increase the heart’s ability to contract effectively and stimulate the kidneys to excrete excess fluid.

Kidney disease

On average, healthy kidneys filter half a cup of blood every minute, removing waste and water that the body excretes as urine. Healthy kidneys are designed to keep the body’s water content at a steady level.

However, in patients with kidney disease, the kidneys lose their ability to effectively remove an adequate amount of water from the blood, causing fluid to build up throughout the body.  Symptoms of kidney disease include decreased urine output, fatigue, shortness of breath and swelling around the eyes and in the legs. Patients can also experience diffuse skin itching, caused by a buildup of phosphorus in the blood.

Some forms of kidney disease can be treated with oral medications. Patients with advanced kidney disease often require dialysis, where a machine is used to filter blood when the kidneys have lost their ability to adequately function.

Sodium overload

Salt is composed of 60% chloride and 40% sodium. Sodium is an electrolyte that helps to control the amount of fluid in the bloodstream and around cells throughout the body.

When you ingest sodium, the kidneys trigger the nearby adrenal glands to release a hormone called aldosterone, which causes the kidneys to excrete potassium and retain sodium. Retained sodium attracts water molecules, leading to an increased amount of fluid in the body. Therefore, eating a salty meal can cause you to gain weight, feel bloated, or notice swelling in your face, legs, ankles, and feet. It can also raise your blood pressure.

With time and enough water consumption, healthy kidneys can filter out the sodium your body doesn’t need, and your body’s water content returns to normal.


The lymphatic system is a network of vessels and lymph nodes filled with fluid that helps immune cells flow throughout the body. If the lymph system malfunctions, this lymphatic fluid can build up in soft tissue, resulting in a condition called lymphedema. 

Lymphedema can occur when lymph nodes are surgically removed or when lymphatic vessels are damaged or blocked. In addition to the swelling, lymphedema can cause discomfort, skin thickening and a sensation of heaviness. Tissue affected by lymphedema is also more prone to infection.

Exercise, compression, and massage are often used to manage lymphedema. In severe cases, surgery is required to remove excess fluid and tissue.

Visit urgent care

If you are experiencing any of these causes of edema or notice you have edema, please visit your healthcare provider. At urgent care you can walk in without an appointment, or you can check in online. We’ll have you back to feeling better in no time. At urgent care we’re here 7 days a week to care for you.






Written by Sarah Thebarge, Physician Assistant