Test Overview

An ultrasound is a type of imaging test that uses sound waves. It takes pictures of the organs and other structures in your body. It can be used in different areas such as the belly, the pelvis, or the arms and legs.

During the test, a small, hand-held device called a transducer is gently passed back and forth over the area being looked at. The device sends the sound waves to a computer, which turns them into a picture. This picture is shown on a video screen. The picture produced by ultrasound is called a sonogram, an echogram, or a scan. Pictures or videos of the ultrasound images may be saved and reviewed later.

Why It Is Done

An ultrasound is done for several reasons. It may be used to look for a blocked blood vessel. It may be used to find the cause of pain in your belly or another part of your body. Or it can be used to look for a cyst, tumour, or abscess that may need treatment. It may also be used to help guide the placement of a needle or other tool during a biopsy.

How to Prepare

In general, there's nothing you have to do before this test, unless your doctor tells you to. Depending on what is being looked at, you may get special instructions such as when you can eat or drink.

How It Is Done

This test is done in an ultrasound room in a hospital, clinic, or doctor's office.

  • Gel is applied to the skin to help the sound waves pass through.
  • The transducer will be pressed against the gel on your skin. It will be moved across your skin several times.
  • You need to be very still while the test is being done.

How long the test takes

Depending on what is being looked at, the test will take about 15 to 60 minutes.

How It Feels

This test usually doesn't cause any pain or discomfort. The gel may feel cold when it is first put on your skin. And you may feel light pressure from the transducer as it passes over the area being looked at.


There are no known risks from having this test.


The scans from the test will be read within a short time.



The organs, tissues, and vessels are normal in size, shape, and structure.

No growths, tumours, fluid, or other problems are seen.

No signs of disease, inflammation, or infection are seen.

Blood vessels and blood flow are normal. No blood clots are seen.


The organs, tissues, and vessels may be abnormal in size, shape, or structure.

Growths, tumours, or fluid may be seen.

Signs of disease, inflammation, or infection may be seen.

Blockages in blood vessels, changes in blood flow, or blood clots may be seen.


Current as of: December 19, 2022

Author: Healthwise Staff
Medical Review:
Caroline S. Rhoads MD - Internal Medicine
Robert G. Pearcey MD, FRCPC - Radiology, Radiation Oncology, General Oncology