Swelling in the lower legs – known as “lower extremity edema” in medical terms – is a problem that often affects older adults.
The good news is that most of the time, it’s annoying, but not terribly dangerous. However, in other cases, swelling in the feet, ankles, or lower legs can be the sign of a new health problem, or a worsening chronic condition.
And, even if it’s “benign” and not related to a dangerous health condition, edema can be a major risk factor for skin breakdown and reduced mobility in aging adults.
Since leg swelling becomes so common as people get older, in this article we’ll demystify leg edema and cover the most important things that older adults and families should know about this condition. In particular, we’ll cover:
- How does edema happen?
- Common causes of swollen ankles or legs in aging adults
- Medications that can cause leg swelling as a side-effect
- How leg swelling should be medically evaluated
- How to prevent and treat leg swelling
- What to know BEFORE going on a “water pill”
How does edema happen?
We notice edema when our shoes are too tight, or we get marks on our ankles from our socks. But what’s really going on inside the body?
Edema happens when fluid moves outside of blood vessels and into what’s called the interstitial spaces of the body. These spaces are also sometimes called the extra-vascular space (which literally just means “outside of blood vessels”), and is basically the moist space between cells, organs, and body parts.
Although you make think of blood vessels as being “waterproof”, physically they are more like a semi-permeable membrane, made of blood vessel cells that usually stay close together, and it’s normal for small quantities of fluid to pass back and forth.
If more fluid than usual passes out of the blood vessels, and this happens in the legs or near the surface of the body, it looks like a swollen or puffy area under the skin.
Fluid can move into the interstitial spaces and cause edema for a few different reasons. The most common causes are
- “Leaky” blood vessels: Sometimes the blood vessel cells don’t stick together as tightly as they should. This can allow fluid molecules to slip through the connections between the blood vessel cells (like gaps between the bricks in a wall).
- This can happen due to severe infection or inflammation, among other things.
- Low levels of protein in the blood: Proteins, such as albumin, help keep fluid inside blood vessels. This is because protein molecules in the blood exert an “osmotic” pressure (also called “oncotic pressure”) that helps retain fluid inside a blood vessel. If protein levels fall in the blood vessel, even if the membrane of the blood vessel is intact, fluid moves outside of the vein or artery to equalize the osmotic pressure across the membrane, and this creates edema.
- Some causes of low albumin levels in the blood include certain types of kidney disease, liver disease, and malnutrition.
- Fluid overload: If there’s more fluid than usual in the blood vessel, it becomes “overloaded.” The extra fluid will be then end up pushed across the blood vessel wall because of high hydrostatic pressures.
Normally, our kidneys regulate body fluid levels by adjusting the amount of water and salt that is excreted or retained. But if those mechanisms fail or are overwhelmed, edema is often the result.
When we look at common causes of edema, keep these different mechanisms in mind. The cause of the edema will play a major role in deciding on the best course of treatment.
What are the most common causes of leg edema
By far, the most common cause of leg edema is chronic venous insufficiency, but there are some other causes that are critical to rule out.
Chronic venous insufficiency
This is the cause in about 70% of older adults with leg edema. To understand chronic venous insufficiency (CVI), we first need to cover how veins work.
Veins are the blood vessels that return blood to the heart so that it can be pumped to the lungs and get oxygenated. Veins don’t have muscles in their linings like arteries do; instead, they rely on a system of valves to keep blood from flowing backwards. Over time, these valves become less effective, and blood can hang around in the veins longer than it needs to – a phenomenon called venous insufficiency.
When venous insufficiency becomes chronic, this can cause varicose veins and/or edema, due to there being extra fluid in the veins. Venous insufficiency can also end up causing phlebitis (inflammation of the veins), ulceration of the skin (sores and wounds) and even sometimes cellulitis (skin infections).
CVI is common, affecting an estimated 7 million people worldwide and causing 3 million to develop venous ulcers, the most common type of leg ulcers. The cost of venous ulcers to the US healthcare system is estimated at 2 to 3 billion dollars a year.
Risk factors for CVI include:
- Advancing age
- Family history
- Prolonged standing
- Sedentary lifestyle
- Lower extremity trauma
- Prior venous thrombosis (blood clots in the veins)
In the section on treatment, I’ll explain how to manage edema due to CVI and share tips on reducing the risk of complications. Keep in mind that leg swelling is something that people live with on a chronic basis and is rarely completely cured. The goals of a treatment plan are to reduce the edema, prevent the discoloration and thinning of the skin, and prevent or heal skin sores.
Congestive Heart Failure (CHF)
Congestive heart failure (CHF) is the most common cause of generalized edema (affecting the legs, abdomen, and sometimes the lower back and even higher on the body), and a major cause of edema of the legs.
Heart failure is a term that we use when the heart muscle is weakened and not pumping blood as effectively as it should. Heart failure is often described as being “right-sided” or “left-sided” depending on which chamber of the heart is most affected. The “congestive” part refers to the backflow of blood into the veins in the lungs (if it’s “left-sided”) or the legs or lower part of the body (if right-sided”). Some people have right-and left-sided heart failure.
In CHF, there’s fluid congestion in the veins, but that’s not the whole story. When CHF is chronic, lasting more than a few weeks, it reduces blood flow to the kidneys, and they respond by causing the retention of salt and fluid in the body. This is an especially important factor when treating the edema associated with CHF.
In CHF, the edema in the lungs, or pulmonary edema, can be much more difficult to live with; it usually causes shortness of breath, coughing, and breathlessness when lying flat to sleep.
CHF treatment frequently involves diuretic medications (also known as “water pills” to relieve symptoms. Some commonly used diuretics used for CHF include furosemide, spironolactone and metalazone. The dosing of diuretics often must be managed carefully to minimize the potential side effects of low blood pressure, potassium depletion, dehydration, and kidney injury.
People living with CHF are usually advised to restrict their daily fluid and salt intake, weigh themselves frequently, and adjust the daily water pill dose depending on their weight, along with regular bloodwork.
In this article, we won’t go into more detail about CHF, as it’s a complicated topic of its own. The main thing you should know is that if you’ve been concerned about leg swelling in an older person, it’s important to find out if they have a history of heart failure or heart problems, especially if they are also reporting symptoms of shortness of breath.
Medication-related leg edema
Some medications can cause or worsen swollen legs. or make them worse. In most cases, the drugs increase fluid and salt retention, causing edema, but for some drugs, such as dihydropyridine calcium channel blockers (like amlodipine) the capillaries become leakier, and in other cases, the exact mechanism for edema isn’t known. Below is a list of medications that may cause edema.
- Antihypertensive drugs
- Calcium channel blockers
- Beta blockers
- Nonsteroidal anti-inflammatory drugs (including over-the-counter painkillers)
- Monoamine oxidase inhibitors
New or worsened leg swelling should always prompt a medical evaluation, to make sure the swelling isn’t due to a medication side-effect. (To learn more about medications to avoid in aging adults, read this article: Medications Older Adults Should Avoid or Use with Caution).
In cirrhosis of the liver, edema may occur in the lower limbs or, more commonly, localized to the belly (called ascites). The liver is where the body makes albumin, a major component of protein in the blood, but in cirrhosis, the damaged liver can no longer maintain adequate production of albumin and other key proteins. The resulting lower blood protein levels mean that fluid will leak out into the interstitial spaces, which can cause edema and also noticeable swelling of the belly.
Diuretics can be used to help people with cirrhosis, and sometimes drainage of the abdominal ascites is performed, with careful management of blood pressure and electrolyte balance.
A kidney condition called nephrotic syndrome is associated with protein leaking out into the urine. This can cause edema in the legs and elsewhere in the body.
A urine dipstick normally checks for protein in the urine, and a more precise check can be done through a urinalysis.
Although most fluid in the body moves through blood vessels, the body also has a network of lymphatic vessels, which connect to lymph nodes and move fluid and immune system cells through the body.
Lymphedema means edema caused by fluid overload in the lymphatic vessels, not the veins. When there’s too much fluid for the lymph system to drain, or not enough capacity in the lymphatic channels, swelling is the result.
Lymphedema is most often associated with a history of cancer and/or lymph node surgery, and usually affects one limb, rather than both. Seventy percent of prostate and breast cancer survivors experience lymphedema as do 80% of those with severe obesity.
This type of edema is treated by elevating the limb as much as possible, the use of compression garments, a special kind of decongestive massage, or microsurgery to enhance the lymphatic system. Of note, treatment with diuretics (“water pills”) is not usually effective.
How Leg Swelling is Medically Evaluated
What to Tell Your Doctor About Leg Swelling
If you’ve noticed new or worsening leg swelling, it’s important to let your health provider know, so that you can be evaluated.
The doctor should check to make sure that you aren’t suffering from a potentially serious problem (such as one involving the heart, kidney, or liver), and will generally try to determine what is causing the leg swelling.
Questions the doctor will probably ask include:
- How long has the edema been there?
- Is it affecting both legs equally, or one more than the other?
- Is it painful? (Venous edema can cause aches, lymphedema is painless)
- What medications are being taken? Any recent changes?
- Does it get better overnight? Or with elevation of the legs?
- Any shortness of breath? Any difficulty lying flat?
Of course, they will also want to take a complete health history, to know whether you’ve ever had cancer, radiation or surgery to your pelvis or legs, and any known heart, liver or kidney problems.
Signs that more urgent evaluation of leg swelling may be needed
Certain signs and symptoms should prompt a more urgent evaluation. They include:
- Breathing symptoms: Shortness of breath, cough, and trouble breathing when lying flat might be indicators of pulmonary edema, from CHF or another cause. If a person has these symptoms along with leg swelling, they should seek medical attention right away.
- Swelling on one side only: Most of the causes of swelling described above will cause both legs to be affected, so if only one leg is swollen, it might be caused by:
- A blood clot, which usually does limited harm in the leg but could break off and travel to the lung causing severe illness or even death,
- Blockage related to a tumor
(Of course, if a person has previously had a blood clot or injury to one leg, it may appear quite different from the other leg and the swelling might be chronically asymmetric, so that needs to be considered as well.)
- Pain: Most of the time, edema due to CVI is painless, although some people experience discomfort similar to an achy tiredness. Severe or significant pain should not be ignored. In particular, a sudden severe pain in the legs or the chest is a reason to seek help without hesitation.
What Your Doctor Will Do
Your doctor will check for “pitting,” by gently pressing on the swollen area. Pitting occurs when pressure to the swollen area leaves a little depression behind for a few seconds to minutes. Most causes of edema are pitting, but if there’s no pitting we would think about lymphedema or a fat deposit (lipedema).
A close examination of the legs is vital, to check for any varicose veins, discoloration of the skin, ulcers or breaks in the skin, and skin dryness. If the legs seem to be different from each other in size, your doctor might measure both limbs to see if there’s true asymmetry.
It’s also important to do an examination of the heart and lungs. Expect your doctor to listen to the breath sounds and heart sounds, and to check your pulse and blood pressure. Doctors will also often examine the belly, to feel the liver and also make sure they don’t see signs of edema outside the legs.
Potential Tests and Additional Evaluation
Based on what you tell the doctor, your past medical history, and what the doctor observes through the physical examination, the doctor will then determine whether additional testing is needed.
Tests that may be ordered include urinalysis (to look for protein in the urine), creatinine (a test of kidney function), TSH (some thyroid conditions lead to edema), glucose, albumin (a major protein found in the blood) and liver function tests may be ordered. (For more on blood tests, see Understanding Laboratory Tests: 10 Commonly Used Blood Tests for Older Adults.)
Tests of cardiac function may be a part of the work-up as well, such as a chest x-ray to look for an enlarged heart or fluid in the lungs, or an echocardiogram, which is an ultrasound study to look at the heart chambers and muscle contractility.
D-dimer is a blood test that can help detect a blood clot, and a doppler ultrasound of the leg can usually find a deep vein thrombosis – a common cause of swelling in one leg only.
If your doctor is looking for deeper causes to explain leg swelling, they may refer you for a sleep study. Sleep apnea, if left untreated, can lead to the right-sided heart failure that we mentioned earlier.
It’s also possible that your doctor might not feel the need to order additional testing. Especially if bloodwork has been done in the past few months and if the symptoms and examination fit with chronic venous insufficiency, it can be reasonable for the doctor to proceed with treatment for this condition.
How Leg Swelling is Treated
As I noted above: most of the time, leg swelling in an older adult is caused by chronic venous insufficiency (CVI), an issue with the leg veins not doing an adequate job to return blood to the heart.
What to know BEFORE starting a “water pill” for leg or ankle swelling
You might think that a diuretic (a “water pill”) will help, and they certainly are often prescribed for this purpose. However, research has shown that they often don’t help much, probably because they don’t really address the underlying issue, which is weak valves in the veins and local fluid overload.
Furthermore, diuretics in older adults can easily cause side effects like dehydration low blood pressure, low potassium levels, and constipation. They also increase urination, which can cause or worsen urinary continence issues. (For more on these issues, see How to Prevent and Treat Dehydration in Aging Adults and Urinary Incontinence in Aging.)
How to treat chronic venous insufficiency in aging adults
So before starting a water pill, be sure to ask your doctor about the cause of your leg swelling and consider trying these strategies first:
- Elevate the legs: raise your legs to at least the level of your heart for 30 minutes 3 or four times a day – this habit uses gravity to help the veins drain the blood from the lower limbs to return to the heart for circulation.
- Wear stockings: compression stockings with a low pressure (15-20 mmHg of pressure) are readily available at many drug stores and are not too difficult to put on and wear. The stockings have higher pressure at the ankle which gradually reduces the higher up the leg it goes. Those with more moderate to severe edema may need to be specially measured and fitted for compression socks, which may require a prescription.
- Reduce salt intake: salt (aka sodium) can worsen edema by promoting fluid retention. Lowering salt intake can also reduce the risk of high blood pressure. Hide the saltshaker and avoid processed food and takeout.
- Exercise the calf muscles: walking and pumping your calves is recommended to reduce the symptoms of CVI and speed the healing of ulcers if present.
Other treatment options for chronic venous insufficiency
- Venoactive agents: these are compounds that act in a variety of ways to relieve CVI symptoms. They improve venous tone, improve lymphatic drainage, fight inflammation, and increase blood viscosity. Examples are horse chestnut seed extract, micronized purified flavonoid fraction (MPFF)and pycnogenol. A large review of scientific studies of venoactive agents showed that they can reduce swelling.
- Skin care: This may not help with edema but is a critical step to prevent ulcers (skin sores), which can occur as a complication of CVI.
- Ulcer care: ulcers on the legs and feet from CVI can be chronic and hard to treat. A specialized wound care team is often consulted to advise about any topical treatments or surgical procedures that can help with healing. All of the measures to reduce edema described above will help with ulcer prevention and healing.
Again, the goal of treatment is to manage symptoms and prevent other problems, like ulcers and discomfort. Most older adults can treat their leg swelling with some of the strategies described above and maintain their usual activities and quality of life.
Treatment of Leg Edema from Other Causes
If edema is not due to CVI, the treatment plan will target the underlying problem, whether it’s heart failure, a medication side effect, a kidney issue, or liver disease.
The Take-Home Messages about Leg Swelling:
Edema (or swelling) of the lower limbs is common in older adults. The most common cause (about 70%) of leg edema is due to Chronic Venous Insufficiency (CVI).
Other serious causes of edema include congestive heart failure, kidney disease, and liver disease. Always be sure to get evaluated for new or worsened leg swelling, to make sure one of these more serious medical problems isn’t at hand.
If the leg swelling is present in one leg only, or if there’s a lot of pain, or if you notice other serious symptoms along with the leg swelling (shortness of breath, chest pain, cough or trouble breathing when lying flat), this could be a sign of an urgent problem which needs medical attention right away.
But again, most leg swelling in aging adults is chronic venous insufficiency. The ideal management of this chronic condition includes “lifestyle” measures such as elevating the legs regularly, using compression stockings, reducing salt intake, and doing exercises which improve fluid movement in the legs.
It’s important to get help from your health providers to manage CVI, because without treatment, it can cause complications such as ulcers (skin sores), infections, and reductions in quality of life.
Diuretic medications (“water pills”) can sometimes help to reduce edema from CVI, but the side effects can be serious: dehydration, potassium depletion, urinary incontinence and low blood pressure. So geriatricians recommend using these medications with caution in older adults. They are also not a substitute for the lifestyle measures listed above.
To learn more about edema, here are some useful links:
- VIDEO: What Causes Swollen Legs with Dr. Didyk
- Treatment of edema (American Family Physician Review)
- Patient education: Low-sodium diet (Beyond the Basics) – UpToDate
- Patient education: Edema (swelling) (Beyond the Basics) – UpToDate
- Phlebotonics for venous insufficiency – Martinez-Zapata, MJ – 2020 | Cochrane Library
- Chronic Venous Insufficiency | Circulation (ahajournals.org)
If you have swollen legs, you’re not alone and there are strategies you can use, without medications, to reduce the symptoms of edema. Like everything, being consistent is key.
I’d love to hear about your experience with leg swelling and what you’ve found to be helpful, or any thoughts about topics for future blog articles. Please leave a comment below and join our mailing list so you won’t miss another article!
Dr. Nicole Didyk is a board-certified geriatrician in Canada and a regular expert contributor to Better Health While Aging. You can learn more from her by visiting her site TheWrinkle.ca, or her aging health channel on YouTube.