Hernia ultrasound: when it is used and what the scan involves

A hernia occurs when an internal part of the body pushes through a weakness in the muscle or surrounding tissue wall. NHS 111 Wales says a hernia usually develops between the chest and the hips, and that in many cases it causes no or very few symptoms, although you may notice a swelling or lump in the tummy or groin, which can often be pushed back in or disappears when you lie down. Coughing or straining may make the lump appear.

The NHS lists types by location: hiatus hernia in the chest, umbilical hernia near the belly button, inguinal hernia where the leg joins the abdomen, femoral hernia in the upper thigh near the groin, and others such as lumbar and stoma hernias. Inguinal hernias are the most common type and mainly affect men, while femoral hernias are much less common and tend to affect more women, according to NHS 111 Wales.

NHS 111 Wales says that a GP will usually identify a hernia by examining the area, and may refer you to hospital for an ultrasound scan to confirm the diagnosis or assess the extent of the problem. In practice, this tends to be when the lump is small, comes and goes, is hard to feel, or when there is pain in the groin without a clear lump.

Local clinical pathways differ. A York and North Yorkshire primary-care pathway states that there is no benefit from an ultrasound for clinically apparent hernias and asks GPs not to order scans to confirm clinical findings, instead referring to surgical clinics, citing European Hernia Society guidance that groin imaging should be reserved for patients with obscure pain or swelling. When imaging is needed in those uncertain cases, ultrasound is suggested first, then MRI with straining if the ultrasound is negative. This pathway is local and was under review, so what you are offered depends on where you live and on the doctor’s judgement.

Ultrasound can also help distinguish a hernia from other lumps. The York pathway says solid lumps such as swollen lymph nodes, lipomas or other masses should be excluded, and a scan may help in that situation.

The NHS says an ultrasound scan can take around 10 to 45 minutes and is carried out by a healthcare professional, with a nurse or healthcare assistant sometimes present. You may need to move clothing aside or change into a gown, and you will lie or sit on a bed. A slippery gel is applied to the skin and a probe is moved over the area, with the lights dimmed. You can ask for a chaperone and are in control of the scan.

For a suspected groin hernia, the BMUS guidance for sonographers explains that the operator will ask you to strain in a controlled way, a manoeuvre known as a Valsalva, because reducible hernias can be missed if the pressure is not raised properly. Coughing is described as a last resort. The guidance suggests the operator may scan with you standing, may compare with the other side, and asks you to point to the area of concern. It also notes that a full bladder can distort the anatomy and hide a hernia, so you may be asked to empty your bladder before a groin scan; follow your appointment letter.

The sonographer is looking for the location, whether it is reducible, what it contains and whether the neck of the hernia is large or small, which are the four things the BMUS guidance says the referring clinician wants to know.

A hernia can become trapped (incarcerated), blocked or have its blood supply cut off (strangulated). NHS 111 Wales says you should go to your nearest A&E straight away if you have a hernia and develop sudden, severe pain, are sick, have difficulty passing stool or wind, or the hernia becomes firm or tender or cannot be pushed back in, because a strangulated hernia or obstructed bowel is a medical emergency.

The NHS lists the following as reasons to get help from NHS 111 if you have a hernia: pain in or around the hernia, a bloated tummy, feeling or being sick, vomiting blood or vomit that looks like coffee grounds, constipation, a high temperature or feeling hot, cold or shivery, and sudden confusion. These warrant same-day assessment rather than waiting for a routine scan.

The result goes to the doctor who referred you. The NHS says you may get it at the end of the appointment or it can take a few weeks, and that you may need a follow-up appointment. If you have heard nothing after a few weeks, contact the specialist or GP surgery.

Once a diagnosis is confirmed, NHS 111 Wales says a GP or hospital doctor will decide whether surgery is needed, taking into account the type of hernia, its contents and the risk of strangulation or obstruction, your symptoms and the impact on daily life, and your general health. Although most hernias will not get better without surgery, some small hernias with few symptoms may be monitored. The York pathway notes that the European Hernia Society considers watchful waiting a safe and acceptable option for men with minimally symptomatic or asymptomatic inguinal hernias, while warning that symptoms often increase over time; this is a decision to make with your surgeon.

The NHS suggests that you cannot always prevent a hernia, but you can reduce the chance of some types by keeping to a healthy weight, being physically active, stopping smoking and seeing a GP for a cough that does not get better. If you have a hernia, avoiding heavy straining and constipation is sensible and the British Hernia Society’s living with a hernia guide, signposted by the NHS, offers further advice.

In the NHS, hernia care follows GP assessment, then referral to a general surgery clinic if needed. Private ultrasound and surgical consultation can speed up diagnosis and are widely used for hernias; the same red flags and surgical decision-making apply.