Ultrasound for Appendicitis: Can Appendiceal Inflammation Be Seen?

Abdominal pain is rarely clear-cut. When appendicitis is suspected, a doctor may order an abdominal ultrasound — but this is only one of the examinations, not a final verdict. Let's look at which examinations help the doctor and why the decision is not made based on a single image.

Can appendicitis be seen on ultrasound?

Yes, abdominal ultrasound is among the studies that help suspect inflammation of the appendix. Ultrasound and CT are used to check for swelling of the appendix. The symptoms resemble other conditions, so the ultrasound result is assessed together with the physical examination and tests.

How abdominal ultrasound is performed when appendicitis is suspected

First, the doctor asks about the pain and palpates the abdomen: in appendicitis, pressing on the lower right area intensifies the pain. A rectal examination may reveal tenderness on the right. A blood test often shows an elevated white blood cell count. Next come blood and urine tests, and if necessary a pregnancy test.

Signs of appendicitis on ultrasound

The image is checked for swelling of the appendix. With inflammation, the appendix increases in diameter from 4–6 mm to 17–18 mm or more, but this relates to the mechanism of disease development, not to the ultrasound picture. The doctor correlates the image with the symptoms:

• Pain initially around the navel, shifting to the lower right after 12–24 hours
• Increased pain when walking, coughing, or making sudden movements
• Loss of appetite, nausea, vomiting, low-grade fever
• Constipation or diarrhea, frequent urination

When ultrasound does not show the appendix

The symptoms are similar to other conditions, and in pregnant women, young children, and older adults they can be atypical: the pain may be less severe, develop more slowly, or be felt in a different location. In older adults, sudden confusion sometimes occurs. Sometimes doctors in the hospital observe for several hours how the condition changes. Abdominal pain can be caused by urinary tract infections, kidney or gallbladder stones, irritable bowel syndrome, Crohn's disease, gynecological conditions, and ectopic pregnancy.

CT for appendicitis: when it is ordered

Ultrasound and CT are imaging studies that aid diagnosis. If CT reveals an abscess, antibiotics may be prescribed first, and the appendix is removed after the infection and swelling have subsided.

Why the diagnosis is not made on ultrasound alone

Diagnostic tests are imperfect: sometimes during surgery the appendix turns out to be normal. The surgeon then removes it and examines the abdomen for another cause of the pain. If symptoms indicate a high probability of appendicitis or there is suspicion of a ruptured appendix, doctors may offer surgery without waiting for additional examinations. Ask the surgeon which examinations were ordered for you and what each result showed.

Abdominal pain alone is not a reason to call an ambulance. Call 103 or 112 if the pain is severe and spreads across the entire abdomen, confusion appears, the skin is pale or mottled, or breathing is difficult — these may be possible signs of sepsis.

This material is for reference: it explains the logic of the examinations but does not replace a doctor's consultation.

This content is for reference and does not replace a doctor's consultation. Medical disclaimer