Your Ultrasound Examination: a
guide for patients
How can I prepare for my ultrasound
examination?
What will happen during my ultrasound
examination?
Your doctor has recommended that you have an
ultrasound examination to find out more about
your problem. This leaflet will tell you what to
expect.
You don’t generally need to do anything
special before you have an ultrasound.
However, if certain parts of your body are
being investigated you may be asked to alter
your diet slightly to help your picture come out
better. Here are some common examples:
You will lie on a couch in a slightly darkened
room, with a screen beside the couch to show
the ultrasound picture. One person will operate
the ultrasound equipment, but there may be
other medical staff in the room.
What is an ultrasound examination?
An ultrasound examination takes a picture of the
inside of your body. However, it is not the same
as an X-ray, because it does not involve
radiation.
Ultrasound works by transmitting high frequency
sound waves through your skin (you won’t feel
or hear anything) which ‘bounce’ off your body’s
internal organs. The patterns of the sound
waves’ movements show up as a picture on a
screen, on which the doctors can see and
diagnose problems. Having an ultrasound
examination is painless and very safe - the
technique is even used on babies.
What is ultrasound used for?
The ultrasound technique is used to examine
many different organs such as your liver and
kidneys, the heart, the pelvis, and major blood
vessels. It can also be used to examine the
eyes, the breasts, and the thyroid gland.
During pregnancy, ultrasound can be used to
take a picture of the unborn baby and to check
that it is healthy. Ultrasound waves can’t pass
through bone (so you couldn’t use it to examine
someone’s brain, as their skull would block the
waves) or through air (so it’s not used for
examining lungs).

If you are having your pelvic area
examined by ultrasound, it will be easier to
see your insides if you have a full bladder,
so you might be asked to drink a few large
glasses of fluid (1 - 1½ pints) 45 minutes
before the examination.

If your gall bladder or pancreas are
being examined, you might have to avoid
eating for 4-6 hours before the test and
drink only clear fluids (e.g. water),
because if there is something in your
stomach this could block the view of your
other organs.

If your liver or kidneys are being looked
at, you may be asked to avoid fizzy drinks
and wind-producing foods like beans for
up to 48 hours before your ultrasound.
This is because the ultrasound waves can’t
pass through air, so it is helpful if you have
as little gas in your digestive system as
possible when you are being examined.
To help the sound waves pass through your
skin, clear oil or gel will be put on your skin over
the area that is being examined. It will wipe off
easily afterwards, but please don’t wear any
clothes that could be damaged by stains.
The ultrasound operator will slide a small handheld instrument like a blunt ended pen over
your skin, which will transmit the sound waves.
It won’t hurt, although if the area is already
tender you might feel a bit uncomfortable if the
operator has to press firmly to get a clear
image. The picture of your insides will appear
on the screen and the operator will examine
these. You might be asked to change position so
that the area being examined can be seen from
different angles. The examination will take
between 10 and 45 minutes.
What will happen after the examination?
You will probably be able to go straight home. If
no other tests are needed, you can eat, drink
and go back to your usual routine right away.
The doctor who decided you should have the
ultrasound will be sent the results of your
examination, and he will discuss these with you.
We hope this leaflet has answered your
questions. Please ask your doctor or the
ultrasound operator if there is anything you feel
worried or unsure about.