What Causes Leg Swelling? A Vascular Surgeon Explains Common and Serious Reasons

Understanding Leg Swelling

Leg swelling, also called edema, is a common problem—but it’s not a normal part of aging. According to Dr. Jason Wagner of Sarasota Vascular Specialists, swelling in the legs often signals an underlying medical or vascular issue that should be evaluated.

Causes That Affect Both Legs

When both legs swell equally, the cause is often related to the body as a whole. Common reasons include:

• Congestive heart failure

• Fluid overload, where the body retains too much fluid

• Medication side effects, especially some blood pressure medications like amlodipine (Norvasc)

If leg swelling starts soon after a medication change, this should be reviewed with your doctor.

When Only One Leg Is Swollen

Swelling in just one leg raises more concern for a vascular problem. These causes include:

• Deep Vein Thrombosis (DVT), a blood clot in a deep vein

• Vein compression or outflow blockage, where blood cannot return properly to the heart

One specific condition is May-Thurner syndrome, where a vein in the pelvis becomes compressed. This can lead to chronic left-leg swelling and sometimes blood clots that require procedural treatment.

Venous Insufficiency: A Very Common Cause

One of the most common vein-related causes of leg swelling is venous insufficiency. This happens when the one-way valves in the veins stop working properly.

Normally, these valves push blood upward toward the heart. When they fail:

• Blood flows backward with gravity

• Pressure builds in smaller veins

• Fluid leaks into surrounding tissue

This leads to symptoms like:

• Leg heaviness or aching

• Burning or itching sensations

• Tightness, pain, or swelling that worsens during the day

If swelling improves overnight when legs are elevated but returns during the day, venous insufficiency is often the cause.

How Leg Swelling Is Diagnosed

Diagnosis typically starts with a non-invasive vascular ultrasound. This painless test checks:

• Blood flow in deep and superficial veins

• Whether vein valves are working correctly

• Signs of clots or blockages

The exam is done in-office and usually takes about 45–60 minutes.

Treatment Options

Treatment depends on the cause, but often includes:

• Compression stockings to reduce pressure and swelling

• Addressing underlying vein valve problems

• Minimally invasive vein procedures, often done in-office with no hospital stay

If one faulty vein is causing the problem and the rest are healthy, treating that vein can significantly reduce—or even resolve—leg swelling.

When to See a Vascular Specialist

You should seek evaluation if you notice:

• New or worsening leg swelling

• Swelling in only one leg

• Leg pain, heaviness, or skin changes

• Symptoms that interfere with daily life or sleep

📞 Call (941) 294-5146 to schedule a consultation with Sarasota Vascular Specialists