A carotid ultrasound, also known as a Doppler ultrasound or carotid duplex ultrasound, uses reflected sound waves to see how blood flows through a blood vessel.

What is carotid ultrasound?

A carotid ultrasound, also called a Doppler ultrasound or carotid duplex ultrasound, uses reflected sound waves to see how blood flows through a blood vessel.

Why would I need a carotid ultrasound?

Carotid ultrasound helps doctors assess the blood flow through major arteries and veins, such as those of the arms, legs, and neck. It can show blocked or reduced flow of blood through narrow areas in the major arteries of the neck.

The test also can find blood clots in leg veins (deep vein thrombosis) that could break loose and block blood flow to the lungs. This problem is called a pulmonary embolism. During pregnancy, a Doppler ultrasound may be used to look at blood flow in an unborn baby to check the baby's health.

Learn more about why you may need a carotid ultrasound.

How can I prepare for my carotid ultrasound?

There is usually no need to restrict foods or fluids, or to make special preparations before a Doppler ultrasound test. Talk to your doctor about any medications you are taking and how best to prepare for the test.

What can I expect during my carotid ultrasound?

A special gel is rubbed on the part of the body being tested to improve sound quality. Then, a transducer (a hand-held instrument that transmits sound waves) is held against your skin while images of the blood vessels are recorded. The test takes about 30 minutes and is painless.

Learn more about what to expect during a carotid ultrasound.

Resources

The following resources have more information on carotid ultrasound: