Leg pain and swelling have many causes, from a pulled muscle to standing all day in the Miami heat. But when swelling appears in one leg, especially with pain or warmth, doctors want to rule out a deep vein thrombosis (DVT). The test they use is a venous Doppler ultrasound. Here is when you may need one and what to expect.
Go to the emergency room or call 911 if leg swelling comes with sudden shortness of breath, chest pain, a racing heartbeat or coughing up blood. These can be signs of a pulmonary embolism.
What Is DVT?
Deep vein thrombosis is a blood clot in a deep vein, most often in the calf or thigh. The danger is that part of the clot can break loose and travel to the lungs. Finding and treating a DVT early reduces that risk.
Symptoms That Can Point to DVT
- Swelling in one leg, ankle or foot
- Pain or tenderness, often in the calf, that may feel like a cramp
- Warmth over the painful area
- Red or discolored skin
- Veins that look larger than usual
Some people with DVT have no symptoms at all, which is why doctors pay close attention to risk factors.
Common Risk Factors
- Recent surgery, especially of the hip or knee
- Long flights or road trips with little movement
- Bed rest, hospitalization or a leg cast
- Recent injury, including a car accident
- Hormone therapy or birth control pills
- Cancer and its treatment
- Smoking, obesity and older age
- A personal or family history of blood clots
Other Causes of Leg Swelling
A Doppler ultrasound helps your doctor separate DVT from other problems, such as:
- Venous insufficiency: weak valves let blood pool in the legs, causing swelling and varicose veins.
- Superficial thrombophlebitis: a clot in a vein just under the skin.
- Baker’s cyst: a fluid-filled sac behind the knee, which can be seen on soft tissue or MSK ultrasound.
- Muscle strain or tear in the calf.
- Peripheral artery disease: reduced blood flow, evaluated with an arterial Doppler ultrasound.
What Happens During a DVT Ultrasound
No preparation is needed. You lie on an exam table while the sonographer applies gel and scans the veins from the groin to the ankle, gently pressing on each section. Healthy veins collapse with pressure; a vein with a clot does not. Doppler measures how blood is flowing. The exam usually takes 30 to 45 minutes per leg. For a detailed walkthrough, read venous Doppler ultrasound: what to expect.
Results
A board-certified radiologist interprets your study, and the report is sent to your ordering physician within 48 business hours. If your doctor suspects a clot that needs immediate attention, they may send you to an emergency department instead of an outpatient center.
Frequently Asked Questions
Can an ultrasound rule out a blood clot in the leg?
Yes. A venous Doppler ultrasound is the standard first test for diagnosing or ruling out DVT.
Do I need to prepare for a DVT ultrasound?
No. You can eat, drink and take your medications as usual.
Is swelling in both legs a sign of DVT?
DVT usually affects one leg. Swelling in both legs is more often related to the heart, kidneys, veins or medications, but your doctor should evaluate it.
Book a Leg Ultrasound in Miami
Imaging Nation Diagnostics performs venous and arterial Doppler studies Monday through Friday. Schedule online or call 786-353-9160. See all of our vascular ultrasound services.
