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Doppler Ultrasound

  • Diane Voyatzis, RD
Publication Type:


Doppler Ultrasound

(Doppler Ultrasonography)


A Doppler ultrasound is a test that can measure blood flow. It uses sound waves that bounce off blood cells.

Reasons for Test

Doppler ultrasound may be used to check blood flow to an area. It may also be needed to check for injuries to blood vessels or see how treatment is working. Common reasons to use it include:

  • Look for the cause of blood pooling in legs, such as valve problems in leg veins
  • Heart valve defects and congenital heart disease
  • Blockage in artery
  • Peripheral artery disease
  • Weakening of blood vessel walls called aneurysm
  • Narrowing of an artery, such as carotid artery stenosis
  • Check baby’s blood flow during a pregnancy

Possible Complications

Most of the time there are no complications with this test.

What to Expect

Prior to Test

The doctor may talk about:

  • Other tests that may need to be done before this test.
  • Fasting before the test, such as avoiding food or drink after midnight the night before. Some people may need a full bladder for their test. The doctor may ask them to drink 6 or more glasses of water without going to the bathroom.
  • Current medicines, herbs, and supplements that you take and if you need to stop taking them before the test.

The doctor may ask people not to smoke, as it can interfere with test results.

Description of the Test

The doctor will put a gel on the skin over the area that will be examined. The gel helps the sound waves travel between the machine and your body.

The ultrasound machine has a hand-held device about the size of a bar of soap. The device is pushed against the skin where the gel was applied. The waves from the device bounce off blood cells or tissue and echo back to device. The doctor can examine the images during the test. The images can also be saved for later review.

The doctor may ask a person to change positions or hold their breath during the test.

Abdominal Ultrasound

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After Test

The gel will be cleaned off. People can go back to their normal activities most of the time.

How Long Will It Take?

About 30 minutes to 1 hour

Will It Hurt?



A radiologist will examine the images after the test. The doctor will then discuss the results and any treatments that are needed.

Problems To Look Out For

After the test, call the doctor if symptoms get worse.

If you think you have an emergency, call for medical help right away.





  • General ultrasound. Radiology Info—Radiologic Society of North America website. Available at:
  • Ultrasound imaging. US Food and Drug Administration website. Available at:
  • Umbilical cord abnormalities. EBSCO DynaMed website. Available at:
Last Updated:

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.