- A Doppler ultrasound test uses reflected sound waves to see how blood flows through a blood vessel.
- It helps doctors evaluate blood flow through major arteries and veins, such as those of the arms, legs, and neck.
- It shows blocked or reduced blood flow through narrowing in the major arteries of the neck that could cause a stroke.
- It reveals blood clots in leg veins (deep vein thrombosis, or DVT) that could break loose and block blood flow to the lungs (pulmonary embolism).
- During pregnancy, Doppler ultrasound may be used to look at blood flow in an unborn baby (fetus) to check the health of the fetus.