FAQs: ultrasound scans

Written by: Dr Michael Webb-Peploe
Edited by: Bronwen Griffiths

Ultrasound scans create a picture of internal body parts using sound waves of a frequency that are outside the audible range of the human ear. During an ultrasound, a small hand-held sensor is pressed against the surface of the body and generates sound waves which then picks up any reflecting echoes from surfaces and tissues within internal organs. The sensor is usually moved over the skin to ensure the organ is viewed from different angles. The images created display on a monitor screen and are recorded for further examination.

Dr Michael Webb-Peploe, a leading cardiologist, answers the most frequently asked questions about ultrasound scans, in particular, abdominal ultrasound scans.

What does the scan look at?

If the ultrasound scan is of the upper abdominal area, then the internal organs imaged include the kidneys, liver, pancreas, gallbladder, spleen and the abdominal aorta. An upper abdominal scan does not image the bowel.

Are there any risks involved?

There are no known risks of ultrasound scans, and they are considered as a very safe investigative procedure.

Do I need to make any special preparation in advance?

To get the most out of the scan, it is advised to not eat or drink for four hours before the scheduled scan. If you do need to drink something, have small sips of water. In addition, it is advised that you wear a two-piece outfit to make the procedure as comfortable as possible.

What happens during the ultrasound scan?

During the scan, either a radiologist or a sonographer will ask certain questions regarding your health and symptoms in question. For the duration of the scan you will be asked to lie down on an examination table. Usually, the lights in the examination room are dimmed so that the images on the monitor can be viewed clearly. Next, a special gel is applied to your skin in the area being scanned. This gel enables the sensor to slide easily over the skin, producing clearer images.

In some scans, you may be asked to turn onto your side, lie flat on your stomach or to stand up. This could be to produce better images of certain organs. If you need help with these positions, support will be given. You may also be asked to take several deep breaths or to hold your breath for a few seconds.

Throughout the scan, the technician performing the ultrasound will be sat or stood next to you as they move the sensor over your skin. Simultaneously they will be reviewing the images produced on the monitor and recording selected images for later examination. Once the scan is finished, the gel will be wiped off and you will be free to get dressed.

Will the scan be uncomfortable?

There is no pain or discomfort associated with ultrasound scans, however, if the scan is to investigate potential causes for abdominal or pelvic pain, then any pressure applied to the skin over an inflamed organ could cause some pain. However, this temporary pain would be no worse than that experienced during a physical examination by your doctor.

How long will an ultrasound scan take?

On average, an ultrasound scan lasts between 10-15 minutes. If there are any delays, you can expect to stay no longer than 40 minutes within the department.

Are there any side effects from ultrasound scans?

There are no side effects following an ultrasound scan. You will be able to drive home afterwards and return to work or normal activities. Also, you will be able to eat and drink normally following the scan.


If you have any other queries about ultrasound scans or require one yourself, make an appointment with an expert.

By Dr Michael Webb-Peploe

Dr Michael Webb-Peploe is an esteemed cardiologist based at The London Medical Specialist Clinic in the capital, who holds a special interest in ischaemic heart disease, hypertension (high blood pressure), heart failure and interventional cardiology.

Dr Webb-Peploe did his undergraduate medical education at Trinity College, Cambridge and St Thomas’ Hospital, London. He underwent his postgraduate training at the Royal Brompton Hospital, Royal South Hants Hospital, Southampton, the Mayo Clinic in Rochester USA and at Hammersmith Hospital (Royal Postgraduate Medical School.) Dr Webb-Peploe was appointed as a physician in charge in the Cardiac Department at St Thomas’ Hospital from 1971 to 1997. He was also a director of invasive cardiology for the Cardiothoracic Unit at Guy’s and St Thomas’ Hospitals NHS Trust from 1997 to 2000.

From 1978 to 2000, Dr Webb-Peploe was appointed an honorary civilian consultant cardiologist to the British Army. He was a consultant advisor in cardiology to the Chief Medical Officer in the Department of Health. Dr Webb-Peploe was a consultant cardiologist (locum) at Guy’s and St Thomas’ Hospitals NHS Trust, to which he is now an honorary and emeritus consultant cardiologist at the hospital.

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