Abdominal (tummy) pain is one of the most common presentations to the emergency department. The causes lie on a spectrum that ranges from harmless to life-threatening. Having a differential diagnosis (ddx) in mind helps guide medics through assessment, triage appropriately, and choose relevant investigations.

Pain in the tummy does not point accurately to its source, as on the hand or face, which makes things a little more tricky. The abdomen can be mentally divided into a 3x3 grid, and important diagnoses considered based on the anatomy lying under each section. It can also be helpful to think across three systems:

Gastrointestinal - the path from mouth to anus, including the liver and pancreas Urogenital - the path from kidneys to urethra, including the sex organs Cardiorespiratory - the heart, lungs, and extended blood vessels

Below are my visual summaries of the important causes for each:

Gastrointestinal