A venous Doppler ultrasound is a diagnostic test used to check the circulation in the large veins in the legs (or sometimes the arms). This exam shows any blockage in the veins by a blood clot or “thrombus” formation.
This test involves no needles, catheters or dye. Ultrasound is used to listen to the flow of the blood through your veins.
Normal Circulation
The veins return blood to the heart. There are two sets of veins in the legs:
- Deep veins – which are underneath the leg muscles
- Superficial veins – which are right underneath the surface of the skin
The veins in the leg deflate easily; blood flows under low pressure and against gravity. Two things help the blood pump more efficiently:
- The calf “muscle pump.” As you walk, calf muscle movement pushes blood upward.
- Venous valves – the one-way valves in the veins that prevent blood from flowing back into your feet.
- DVT (deep venous thrombosis)is a serious health concern, because it is possible that the clot could break off and travel to your lungs. It is then referred to as a pulmonary embolus. The risk of pulmonary embolus is decreased if you recognize the symptoms of a DVT quickly and get it treated right away.
- Superficial thrombophlebitis is a clot that has formed in the veins near the surface of your skin. Clotting can occur after injury or in old varicose veins. Superficial thrombophlebitis usually responds very well to local treatment.
- Chronic venous insufficiency (CVI)
- is a condition that occurs when the venous wall and/or valves in the leg veins are not working effectively, making it difficult for blood to return to the heart from the legs. CVI causes blood to “pool” or collect in these veins, and this pooling is called stasis.
Thrombophlebitis
Is an inflammatory process that causes a blood clot to form and block one or more veins, usually in your legs. The affected vein might be near the surface of your skin (superficial thrombophlebitis) or deep within a muscle (deep vein thrombosis, or DVT).
Risk Factors
No one understands completely why some people are more likely than others to develop a DVT. Some situations increase the chance of clots forming in the deep veins:
- Surgery or injury
- Long-term bedrest or immobility
- Smoking
- Obesity
- A history of venous thrombosis
- Pregnancy
Diagnosis
If your doctor thinks you might have a venous disorder, he or she may order a diagnostic exam to determine what type of a problem you have and how severe it might be.