Leg & Feet Swelling: Causes, Prevention and When to Seek Medical Attention

There are dozens of reasons for swelling in the legs and feet, ranging from harmless to serious to downright dangerous. When should puffy ankles and bloated toes trigger a trip to the doctor?

“Leg swelling isn’t, perhaps, the sexiest of all topics, but it is super common. And when you have leg swelling, you want to have it taken care of,” says Ian Del Conde, M.D., a cardiologist and vascular medicine specialist with Miami Cardiac & Vascular Institute, part of Baptist Health South Florida. “The best thing is to try and understand what has triggered and perpetuated the swelling.”

Dr. Del Conde talked about causes, treatments and the symptoms that signal a serious issue on a recent episode of the Baptist HealthTalk podcast, hosted by Jonathan Fialkow, M.D., deputy medical director and chief of cardiology at Miami Cardiac & Vascular Institute. Check out the Q&A below for answers to some of the most frequently asked questions about swelling in the legs and feet.

Dr. Fialkow:
What actually causes the swelling and puffiness that we may feel or see in our legs and feet?

Dr. Del Conde:
“There are many different causes for leg swelling. When a patient comes to see us, we have to think of all the different possibilities, but to keep it simple, let’s remind ourselves of the force of gravity. Fluid will fall to the lowest part of the body, which are the legs. So, any fluid retention in the body will present as swelling. That’s No. 1.

“No. 2: Blood has to flow against gravity to reach the heart. And because we don’t have a pump at the very lowest part of the legs, the only thing that can pump blood upwards is movement. When you contract your calf muscles, that effectively serves as a pump. And when you’re not using your calf muscles, for example, because you’ve been sitting in a car for five hours on a trip or a long plane ride, then that also causes leg swelling.

Dr. Fialkow:
What are the more common symptoms?

Dr. Del Conde:
“A change in the contour of the ankles and the feet. You can lose the shape of the ankle. And you can also notice that the shoes that you normally wear and that normally fit well, no longer fit well. They’re tight. And your socks, if you use them, can leave marks behind.

“And I would say almost regardless of the cause of the swelling, it will worsen as the day goes on. The more upright you are, the more the gravity will have an effect on all the fluid and the swelling will get worse.”

Dr. Fialkow:
Would you say pretty much anyone that has swelling has a serious medical condition, or would you say it’s more commonly benign?

Dr. Del Conde:
“The vast majority of people will have a completely benign cause of their swelling and it should not be a major concern. However, there are different medical conditions that manifest themselves as leg swelling. And to think mechanistically about this, broadly, it’s usually a plumbing issue and it’s a plumbing issue that can originate in the heart, or it’s a plumbing issue that has to do with the veins that take blood from the legs back to the heart. And lastly, there are a few medical conditions that can cause pretty significant leg swelling.”

Dr. Fialkow:
So, what would be some of the more frequent benign conditions?

Dr. Del Conde:
“One of the more common things that I see are people who have been on a trip, they’ve changed their diet, perhaps more salt intake, less physical activity. And then they notice that their legs are swollen. That’s classical. People who have taken new jobs and are on their feet or sitting all day long, they can also experience that. Other common conditions are medications. For example, some of the medications that we use to treat high blood pressure, a family called calcium channel blockers, can also cause leg swelling.”

Dr. Fialkow:
Do you recommend changing the job or getting off the medication? Or are there levels where it’s just a finding and if it doesn’t bother you, don’t worry about it?

Dr. Del Conde:
“Leg swelling by itself is not dangerous. If it’s not bothering you and you’re doing well, for example, on a medication that is causing the swelling, just continue the medication, why change it? We only make changes to medications when patients are frankly uncomfortable with the swelling.”

Dr. Fialkow:
What can help people with jobs that require them to stand most of the time?

Dr. Del Conde:
“So, for example, if you’re a hairdresser and you’re on your feet all day long, you’re going to be immobile, not using your calf muscles, as we mentioned. So, fluid is going to go to the lowest part of your body. So, for people in that situation, use of compression stockings works great. They actually feel better. They’re more comfortable. Typically, in South Florida, you need an air-conditioned room to feel comfortable with compression stockings. If you mostly work outdoors, with the heat and the humidity, compression stockings may not be a great option. So, sometimes we can use low doses of diuretics for some people.”

Dr. Fialkow:
What is lymphedema and what does it have to do with leg swelling?

Dr. Del Conde:
“Lymphedema is incredibly common. When we talk about the vascular system or the circulatory system, we typically think about arteries and veins. Well, there’s a third type of vessel called the lymphatic. The lymphatics suck all the fluid around the tissues, and they return it to the general circulation. And when those vessels, those lymphatics, are damaged, for whatever reason, then your body’s ability to reabsorb that fluid is impaired. And you develop a very special type of swelling called lymphedema that has its own set of features that is very commonly misdiagnosed.

“The difference between the way lymphedema looks and general swelling looks is that in lymphedema, the toes of your feet will also get swollen. They get very thick to the point that you can’t really lift the skin off the top of your toes.”

Dr. Fialkow:
Let’s talk about medical conditions that more disconcerting, as you mentioned. The big one that people are concerned about are blood clots. Are there any signs or experiences that if someone notices some swelling, we may think it is more likely related to a blood clot?

Dr. Del Conde:
“When somebody suddenly develops swelling in just one leg, this is what in medicine we would call, unilateral leg swelling. When it’s unilateral, definitely seek attention. If you wake up and you have one swollen leg and there was no trauma, you didn’t twist your leg or anything, seek medical attention that same day, don’t delay it. It could be a blood clot.

“When it’s both legs, if it happened very quickly, it’s significant. I mean, you’ve lost the contour of your ankles, for example. Yes. Let’s figure out why this is happening. Let’s rule out medical conditions. When it’s very slow, very gradual, very painless and your instincts tell you that this is after a long trip that you took — you ate more, et cetera — then I think it’s okay to wait.”