The Reason Why Only One of Your Legs is Swollen

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There is a very common question among patients at USA Vein Clinics: “why is only one of my legs swelling?” Chances are good a lot of people have experienced one leg swelling to some degree at some point in their lives, whether it was due to a sprain of some sort, or something more serious.

If the injury that caused the swelling was incurred from a sports injury or fall, then it makes sense as to why swelling may occur in only one leg. However, if it seems your swelling came out of nowhere and is only occurring in one leg, that could mean more serious vein issues.

Let’s take a look at some of the reasons why only one of your legs is swelling.

Common reasons for one leg swelling

Leg swelling happens because fluid is trapped in your leg tissues, something commonly referred to as edema. Some of the reasons one leg swelling can happen include:

Sedentary Lifestyle

One of the leading causes of vein disease is leading a sedentary life. Sitting or standing for long periods of time can really take a toll on your body in a number of ways, but particularly in your vein health. Being sedentary makes it more difficult for your body to pump your blood back up to your heart with ease, and that is where vein problems come in.


Another major contributor to vein disease is being overweight. The additional weight leads to additional pressure on your body and your veins, which means an increased chance of damaged veins. Damaged veins can show themselves in a number of different ways, including swelling. This can happen in both legs but also in just one.


Superficial vein thrombosis (SVT) is a blood clot that occurs right below the surface of your skin and can lead to swelling.

If SVT isn’t treated, it can lead to something more serious: deep vein thrombosis (DVT). A blood clot such as this has the potential to break loose from your leg and travel up to your heart, thus making it potentially fatal.

Chronic Venous Insufficiency

All of the above could be reasons why someone is suffering from chronic venous insufficiency and thus dealing with swollen legs. With this vein issue comes dilated veins that appear as either spider veins or varicose veins as well as the dreaded leg swelling that seems to get worse as the day progresses.

Explore the chart below that shows different symptoms associated with vein disease to better understand what you may be experiencing:


The only way to ensure that your swollen leg doesn’t mean something more serious is to schedule a consultation with a vein specialist.

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A swollen leg is the type of thing you don’t want to just wait to heal on its own, in case it isn’t something that is capable of doing so.

At USA Vein Clinics we offer minimally-invasive vein treatment options to get to the bottom of your vein issues that may be causing your leg to swell. And these treatments will have you back to normal almost immediately after the procedure.

Some of our top vein treatments at USA Vein Clinics include:


Sclerotherpy is used to treat small and medium leg vein issues, mostly commonly spider and varicose veins. It is performed by your doctor injecting the damaged vein with a liquid that closes the vein.


This approach to varicose vein treatment is also referred to as endovenous adhesive ablation or vein glue. VenaSeal is performed by your doctor using a small catheter to put medical adhesive into your damaged vein to close that vein. This helps to redirect blood to healthy veins.

Radiofrequency Ablation (RFA)

Radiofrequency ablation is used to treat large vein disease and large varicose veins on your legs. These veins are usually below the surface and not able to be seen without ultrasound. It is performed by your doctor inserting a small catheter into the diseased vein. Through this catheter, heat is delivered to collapse the vein.

Endovenous Laser Therapy (or ELT)

ELT is an effective method for eliminating visible, painful varicose veins. In this procedure, laser energy is delivered directly into the varicose vein, which heats the vessel walls and seals it closed. The laser energy is delivered via a narrow fiber that is inserted into the vein using a micro-incision. The incision is too small to require sutures and leaves no visible scarring afterward. The treated vessel is reabsorbed by the body over time, while blood is rerouted to healthy veins nearby. This procedure is performed in the doctor’s office using local anesthesia and requires no downtime.


This treatment works best for removing varicose veins near the surface of your skin. Phlebectomy is performed by your doctor making a number of small punctures in your skin, and through those punctures, removing the damaged vein. This approach to vein treatment typically occurs without the need for stitches, and is often done with ELVA or radiofrequency ablation.

Give your swollen legs some relief.

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Medically Reviewed By:

Yan Katsnelson 2 M drive 1 1

Dr. Yan Katsnelson is a philanthropist, business owner, and highly skilled cardiac surgeon. He is the Founder and CEO of USA Vein Clinics, which is part of USA Clinics Group, the parent company of USA Fibroid Centers, USA Vascular Centers, and USA Oncology Centers, with more than 100 facilities nationwide. Dr. Yan has established himself as a strong advocate for accessibility and affordability of the most advanced medical care close to home. His mission is to create a positive experience for each patient with compassionate, personalized, and expert care.

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