Why we ask you to drink water before an ultrasound

Ultrasounds are a common diagnostic imaging test used to see inside the human body. They are often used to look at the baby in pregnant women, and can also be used to diagnose medical conditions. 

If your doctor has directed you to have an ultrasound, you will have been instructed to drink water first. Find out what an ultrasound is and why it’s important to follow water intake directions. 

What is an ultrasound?

An ultrasound uses sound waves to create an image of the inside of the body. It is a painless and safe test that can be used to look at various parts of the body, including the:

• heart
• blood vessels
• organs
• muscles
• joints
• tendons

Ultrasounds can also be used during pregnancy to check on the health of the baby. They are often used to look at the baby’s:

• size
• position in the uterus (womb) 
• placenta (afterbirth)
• amount of amniotic fluid surrounding the baby

Why do we ask you to drink water before an ultrasound?

When you come in for an ultrasound at Xplore Radiology, we might ask you to drink water first. The reason for this is that the full bladder creates a window to help show the baby and organs or for a renal ultrasound, a full bladder helps us visualise the wall of the bladder.

For most ultrasounds where you require a full bladder. You might need to drink 1 litre (four cups) of water one hour before your appointment. You should not empty your bladder once you have started drinking the water.

You may feel like you need to go to the bathroom during your ultrasound, but it is important that you hold it in until after the test is done. If you empty your bladder before the ultrasound is finished, we may not be able to obtain all of the images we need and you may need to come back for another appointment.

If you have any questions about how much water you should drink or what type of ultrasound you are having, please ask your technologist or doctor. They will be happy to help!

Book your ultrasound with Xplore Radiology

You can book an ultrasound directly with Xplore Radiology via our online booking form or by calling our practice near you.  We’re located in 4 convenient locations.