Asymmetric swelling is not something to wait out. When one leg swells and the other doesn't, it's a signal — and the most important cause to rule out is a blood clot.
When one leg swells and the other doesn't, that asymmetry matters. A venous duplex can check for a blood clot in under 30 minutes — at your home, this week. No referral. No waiting room.
When both legs are the same size, a systemic cause (like heart or kidney issues) is more likely. When one leg is swollen, the cause is usually local — something specific to that limb's circulation or lymph system. There are three primary causes to understand.
A blood clot inside a deep leg vein blocks the return of blood toward the heart, causing the leg to swell, feel heavy, and sometimes become warm or red. DVT can develop after prolonged inactivity, surgery, illness, or for no obvious reason. It is the most urgent cause to rule out, because a clot can break free and travel to the lungs — a pulmonary embolism. A venous duplex ultrasound can directly visualize the vein and identify or rule out clot presence.
Veins contain one-way valves that keep blood moving upward toward the heart. When those valves weaken or fail — often more severely in one leg — blood pools in the lower extremity, leading to chronic swelling, skin discoloration, and varicose veins over time. A venous duplex can assess valve function (venous reflux) directly and identify which segments are failing.
Lymphedema is swelling caused by a damaged or blocked lymphatic system. It often follows cancer treatment, surgery, or infection. A venous ultrasound cannot diagnose lymphedema directly, but it is the right first step — because ruling out DVT and venous insufficiency is essential before a lymphedema diagnosis can be considered. If both vein-related causes are ruled out, lymphedema evaluation with your physician becomes the next step.
A Venous Duplex Ultrasound is the standard-of-care imaging study for one-sided leg swelling. It combines real-time B-mode imaging of the vein wall with Doppler blood flow assessment — allowing the sonographer to see whether a clot is present and whether valves are functioning properly. The exam covers the full length of the deep venous system from the groin to the calf. Price: $397. No referral required.
The traditional path: Call your PCP. Wait days for an appointment. Get referred for imaging. Wait for a hospital outpatient slot. Results in 1–2 weeks. That timeline stretches into 3–6 weeks if you're uninsured or navigating a busy practice.
The BPD path: Book online today. Emanuel Papadakis, RDCS, RVT, comes to your home this week with hospital-grade portable equipment. The full venous duplex is complete in under 30 minutes. Written results within 24–48 hours. If a clot is found, you'll know — and can act immediately.
With DVT, speed matters. The sooner a clot is identified, the sooner anticoagulation can begin — which dramatically reduces the risk of pulmonary embolism.
You'll lie comfortably on your back or side. Emanuel will apply a small amount of ultrasound gel to your leg and move a hand-held probe along the surface of the skin — from the groin down to the calf. There are no needles, no radiation, and no discomfort. The probe gently compresses the vein at intervals to check for clot (a technique called compression ultrasound), and Doppler flow patterns are recorded throughout. You'll be able to see the images on the screen in real time.
The entire exam takes 20–30 minutes for a single leg. A complete written report is delivered within 24–48 hours, including findings and — if relevant — recommended next steps.
Asymmetric leg swelling — where one leg is noticeably larger than the other — is an important clinical sign. The most urgent cause to rule out is deep vein thrombosis (DVT), a blood clot inside a leg vein. Other causes include chronic venous insufficiency or lymphedema. A venous duplex ultrasound can identify or rule out DVT and assess valve function within a single session.
DVT symptoms can include swelling in one leg, warmth or redness along the calf or thigh, and aching or heaviness. However, roughly half of DVT cases have no obvious symptoms at all. The only reliable way to detect or rule out a blood clot is with a venous duplex ultrasound, which directly visualizes the vein and checks for clot and blood flow simultaneously.
A venous duplex ultrasound uses sound waves to create images of the veins in your leg and measure blood flow in real time. It is completely non-invasive and painless — no needles, no radiation. A small probe is moved along the surface of the skin with ultrasound gel. The exam typically takes 20–30 minutes and can be performed at your home.
No referral is required to book with BlackPoint Diagnostics. You can schedule directly, and written results will be available within 24–48 hours. If a clot or valve problem is identified, the report will include findings and recommendations you can bring to your physician.
Southern Maine · Mobile Service · This Week
A venous duplex ultrasound at your home can check for a blood clot or valve failure this week. $397 flat. No referral. Written report in 24–48 hours.
Book Your Venous Duplex$397 · No Referral · Southern Maine · Evening & Weekend Availability