Are there any risks associated with ultrasound?

What ultrasound is

Ultrasound is a type of scan that uses sound waves to create images of the inside of the body. It is commonly used in NHS and private healthcare settings to look at organs, blood flow, and babies during pregnancy.

Unlike X-rays or CT scans, ultrasound does not use ionising radiation. That is one reason it is widely considered a low-risk imaging method.

Are there any risks?

For most people, ultrasound is very safe. The scan itself is non-invasive, and the probe is moved over the skin or placed inside the body in some cases, such as a transvaginal scan.

There are no known harmful effects from diagnostic ultrasound when it is used correctly by trained healthcare professionals. This is why it is often used when doctors want a safer first-line scan.

Possible discomforts

Although the scan is usually painless, some people may find it mildly uncomfortable. A full bladder, pressure from the probe, or having to lie still for a while can cause temporary discomfort.

Internal scans, such as transvaginal or transrectal ultrasound, may feel awkward or uncomfortable for some patients. Healthcare staff should explain the procedure and help reduce any distress.

When caution is needed

Ultrasound is generally safe in pregnancy and is routinely used during antenatal care in the UK. However, it should only be performed when medically appropriate and by trained practitioners.

Very prolonged or unnecessary exposure is avoided as a precaution. Diagnostic ultrasound is different from other uses of sound energy, and it should not be used casually or without a clinical reason.

Allergic reactions and infection risk

The scan itself does not usually cause allergic reactions, but some people may react to the gel used on the skin. This is uncommon and is usually mild, such as itching or irritation.

There is also a small risk of infection with internal scans if proper hygiene procedures are not followed. Clinics reduce this risk by using clean equipment and appropriate infection control measures.

Who should speak to a clinician first?

Most people do not need to worry about ultrasound risks. If you have had pain, a previous reaction to scan gel, or concerns about an internal scan, it is sensible to mention this beforehand.

If you are pregnant and unsure why a scan has been recommended, ask your midwife, GP, or sonographer. They can explain the benefits, any possible risks, and what the scan is intended to check.

The bottom line

Ultrasound is one of the safest medical imaging tools available. For the vast majority of patients in the UK, the main issues are minor discomfort or practical concerns rather than serious side effects.

If you have questions about your own situation, speak to the healthcare professional arranging the scan. They can give advice based on your symptoms, medical history, and the type of ultrasound being used.