Edema: Causes, Symptoms, and Treatment

By Steven Gershman DPM  /  September 13, 2022 Blog Home

What is edema?              

There are many types of Edema, but they are all characterized by buildup of fluid in the tissues of the body causing swelling. It is commonly called "fluid retention" and is often seen in the extremities and as such it is known as "peripheral edema". Edema can also be seen in the face, lungs, and abdomen. This blog mainly will deal with peripheral edema in the lower extremities, i.e., the lower legs, ankles, and feet.

Generally, edema in the peripheral tissue is categorized as either pitting or non-pitting. Pitting edema is diagnosed by pushing on the area of swelling and seeing if there is an indentation or pit in the tissue. It usually lasts for a few seconds.

With non-pitting edema, which is more severe edema, the tissue is so firm it doesn't indent when pushed on. It is like a water balloon filled fully. The fluid is body water or natural/isotonic saline, not blood.

Edema causes

In the legs the veins have valves that operate as "check valves" to prevent blood from going down to the feet due to gravity. Heart pumping action pushes blood through arteries down to the feet. The blood needs to return to the heart for re-circulation through veins. However, there is no true pump pushing the blood up the legs. Blood pressure through the system and the leg muscles contracting pushes the blood up the leg veins while the valves prevent backflow down against gravity.

Incompetence of the valves allows blood to pool in the legs and feet eventually leading to edema and swelling. When blood stagnates or pools in an area, water leaches out of the blood into the surrounding tissue.

Valve incompetence can occur due to the following reasons:

  • As we age
  • Sitting with the feet down on the floor for many hours
  • Varicose veins which in many cases is a genetic weakness in the valves

    Regardless of the cause, as the valves in the legs become incompetent, the blood pools and causes swelling which puts pressure on the veins dilating them and further hindering the valves from working efficiently leading to more swelling. It is a vicious cycle.

    Besides vein issues, edema can be caused by a variety of other problems that can affect both legs.

    • Heart disease: is a major cause, specifically congestive heart failure or CHF. As the heart begins failing as a pump, fluid will stagnate in areas like the legs and lungs and cause swelling/edema. Also, there is less blood going to major organs like the kidneys causing fluid retention.

    • Kidney disease: causes fluid retention and edema as the kidneys can't eliminate enough fluid.

    • Liver disease: causes edema in the legs and abdomen especially if there is cirrhosis.

    • Specific medications: calcium channel blockers and beta blockers can have peripheral edema as a side effect and is seen often in the ankles and lower legs.

    • Sodium: salt in the diet is another culprit in edema. Salt causes fluid retention which manifests as edema.

    • Alcohol: causes dilation of the veins which leads to edema. Susceptible people will have widespread vaso-dilation of the face, arms and legs when consuming alcohol. Eventually the veins stay dilated with chronic edema resulting.

      Another type of edema is lymphedema. It is often quite severe with large swollen legs or arms. Usually it is single limb. Lymphedema is often a genetic issue but can also be caused by cancer treatment and surgery. The lymph system which is part of the immune system is compromised causing swelling.

      Symptoms of edema


      Swelling is the big symptom of edema. In this blog I will specifically discuss leg swelling, ankle swelling, and foot swelling. But other symptoms ay also present themselves, such as the ones below.

      • Discoloration to the skin: In the lower legs and ankles when the edema is caused by incompetent veins, changes occur to the skin. Chronic edema often leads to a brownish or reddish discoloration of the skin on the front of the shins and down to the ankles. This discoloration is due to hemosiderin deposits. Hemosiderin is a pigment from the iron/hemoglobin in the blood that leaches out of the blood into the tissue and skin. It permanently stains the skin. I tell my patients it is "rust deposits" from the iron in their blood. With edema there is fluid pressure in the tissue that builds up forcing the iron into the tissue and skin especially as the blood stagnates or pools. Hemosiderin is a good indicator that the edema is affecting the skin and problems are going to occur if not dealt with and stasis dermatitis can then occur.

      • Skin inflammation: Stasis dermatitis is an inflammation of the skin causing a rash which itches, burns, and can be painful. In severe cases, stasis dermatitis can cause breakdown of the skin resulting in open wounds or ulcers that are painful and can become infected with resulting in cellulitis.

      • Skin thickening: Chronic edema can also cause thickening of the skin in the lower legs from the inflammation. This is permanent. The skin becomes thick, irregular, rough and almost elephant like in texture. It often drains fluid or weeps chronically and can blister.

      • Neurological disorders : Another issue with edema is neurological. Edema causes pressure in an enclosed space where the nerves run down to the feet from the legs. The nerves become compressed causing pain and or numbness in the feet. It is similar to diabetic neuropathy.

      • Swelling: Swelling of the feet from edema makes it difficult to wear shoes as the feet are simply too large to fit shoes. Many of my patients with edema come into the office wearing worn stretched out slippers or shoes way too large and stretched out.

      How to treat and prevent edema


      Treatment of Edema will depend on what triggers it. Some treatments are simple and can be done on your own at home while others will require medical intervention.

      • Elevation of the feet and legs: As gravity is one of the main culprits with edema, elevation of the legs/feet is a mainstay in treatment. Sitting for long periods with the feet down on the floor can cause or add to edema. Many older patients sit a lot at home with their feet on the floor. I recommend a recliner to them. Basically, elevation of the legs higher than the waist, as in a recliner, works. With the feet higher than the waist, gravity works to pull the fluid back toward the heart. Elevating even higher where the feet are higher than the heart is better BUT often uncomfortable and not practical.  

      • Compression Stockings: This is the real treatment for edema. By putting pressure up the legs, the fluid is pushed back from the lower areas up to the upper legs and midsection where it is pumped back to the heart. Pressure needs to be graded so it is highest down near the ankles and gradually lessens going up the legs. Support hose up to the knee at least are the mainstay in treatment. There are several strengths of hose starting from mild compression over the counter type all the way up to prescription higher pressure stockings. Prescription stockings need to be custom fitted carefully by a trained professional. These need to be applied when first getting up in the morning before getting out of bed and worn until bedtime. People who stand a lot in one place at work and have the tendency toward edema or varicose veins should consider wearing support hose to reduce the chances of severe edema with its permanent damage.

      • Compression Wraps: In severe cases of edema such as in stasis dermatitis, or when ulcers occur or with lymphedema it is often required to wrap the legs in heavy compressive dressings. This is done first by a medical professional and can be followed at home by a nurse or the patient. Often several layers of wrap are used, and it is cumbersome. However, in many cases this is the only way to control the fluid and the damage. Prevention is still the best treatment here as once the edema reaches this point it often becomes a chronic issue of wrapping the legs. 

      • Avoiding Salt: Reducing salt in the diet can help reduce fluid problems and edema. I have had patients with leg edema who ate pizza daily and swelled up. Reducing the pizza in the diet in those cases reduced the swelling.

      • Limiting Alcohol: Reducing alcohol also makes a big difference. I have seen remarkable changes in the edema in patients who took my advice in this area.

        For the other issues causing edema, patients should work with their medical professional to best manage the condition. In many cases the edema will improve as the medical issue is stabilized. If medication side effects are causing edema, talk to your prescriber about it and how to manage the side effects.

        Shoes for Edema


        As written about earlier, shoes can become an issue with edema resulting in swollen feet and ankles. Shoes for people with swollen feet and ankles can help prevent further swelling and pressure and enable people to function normally.

        Edema shoes should have the following features:

        • Stretchable to accommodate the increased size and the constant changes in size that can occur from day to day and during the day. Usually fabric uppers that incorporate stretch are able to do this best. This type of shoe conforms to your unique foot shape and size and creates a pressure free environment for the feet. Orthofeet manufactures stretchable shoes that serve this purpose well. I have recommended these shoes often for edema and many diabetics. 

        • Multiple adjustability features are important as they allow you to customize the fit to your particular foot shape. Straps, laces and bungee cords in various locations, such as the heel, instep and forefoot can be loosened to accommodate a swollen foot. The more adjustability the shoe has the better it will fit your feet and accommodate the swelling. 

        • Wide widths are especially helpful with edema. Most brands only design shoes in medium width (B) which is way too narrow and constricting for a swollen foot. Not only will your foot not be able to fit into them, but if they do, it will further exacerbate the condition. Many orthopedic brands such as Orthofeet offer extended widths that go up to 6E!

        • Extra depth from the heel to toe area provides more space for the expanded foot and makes a comfortable foot space. 

        • Shoes designed with a round and wide toe box are always recommended since they allow the toes to flex and extend properly. The generous space prevents the formation of bunions and hammertoes and offers a pressure free environment for swollen toes. This will eliminate or reduce friction and rubbing between the toes which can lead to calluses, blisters or other serious problems.

        • Orthotics built directly in the shoes can provide added benefits for edema in the feet. Swelling in the ankles may impact your gait. Orthotics are designed to support the arch and align the body from the ground up. 

          Many patients with swollen feet prefer to wear slippers as their design is usually less constructing and structured and are fairly stretchable. However, most slippers often lack the support and protection of well-made orthopedic shoes. If opting for a slipper, a quality one that not only stretches but has some support is critical. Poorly made slippers can lead to falls and often severe injury and don't protect the feet from objects on the ground or furniture.

          As mentioned above, I recommended Orthofeet shoes to many of my patents and wear them myself. It is an orthopedic footwear company that specializes in designing shoes for swollen feet. All the shoes, including the edema slippers, are designed with built in orthotic insoles, extra depth, a round toe box and are available in wide widths. The edema styles are made with stretch uppers and several adjustability features to achieve a perfect fit.

          Socks for Edema


          Have you ever experienced rings around your ankles and legs after removing your socks? Wearing the right type of socks for edema can also be critical in managing symptoms. Edema socks are uniquely designed with a non-binding and non-constricting shape and yarns to eliminate pressure. Orthofeet also offers socks for swollen feet that are made of viscose rayon fabric and are super soft against the skin.

          Finally, edema as in all medical issues, is best managed early. If you start noticing swelling near your ankles or pitting skin or marks such as rings around the lower legs when you remove socks, it is time to start thinking of edema and how to control it. Many of the changes that can occur with edema later are permanent. So, prevention is so critical. When in doubt, talk to your medical provider about it.