Appendicitis

Appendicitis is inflammation of the appendix, a small finger-shaped pouch attached to the start of the large bowel. It usually happens when the appendix becomes blocked, allowing bacteria to multiply and the appendix to swell, become infected and inflamed. It is one of the commonest causes of sudden abdominal pain needing surgery, most often in older children and young adults but possible at any age. The classic story is pain that begins vaguely around the navel and, over hours, moves to and becomes sharp in the lower-right abdomen, along with loss of appetite, nausea, sometimes vomiting, and a low-grade fever; the area becomes tender. The presentation can be less typical, especially in young children, pregnant women and older adults, which can make it harder to recognise. The reason it is treated urgently is the risk that an inflamed appendix bursts (perforates), spilling infection into the abdomen (peritonitis), which is far more serious. Treatment is usually surgical removal of the appendix, sometimes with antibiotics.

• White cell count (WBC) and neutrophils — usually raised, reflecting infection/inflammation.
• CRP — commonly raised; rising markers support the diagnosis.
• Urine test — to help exclude a urine infection or kidney stone that can mimic it.
• Pregnancy test — in women, to exclude pregnancy-related causes.
• Ultrasound or CT scan — imaging to confirm when the diagnosis is unclear. Blood tests support the assessment, but appendicitis is diagnosed clinically and with imaging, not by blood tests alone — and a normal white count does not exclude it.

• Pain that starts around the navel and shifts to the lower-right abdomen, becoming sharp
• Pain worse with movement, coughing or pressing the area
• Loss of appetite
• Nausea and sometimes vomiting
• A low-grade fever
• Tenderness in the lower-right abdomen
• Sometimes constipation or diarrhoea Less typical in young children, pregnancy and older adults.