Medicine is a dicipline of uncertainty. So clinicians are always looking for indicators of certainty. We’re looking for signs. Medical signs.

• The psoas sign indicates an inflamed retrocecal appendix.
• A sentinel node is a classic sign of dissemination of cancer into the chest.
• The Cheeto finger sign (telltale orange fingers reflecting the recent consumption of puffed cheese snacks) indicates that a child hospitalized for acute gastroenteritis is ready for discharge.

These bellweather indicators offer safe mooring for survival in a medically complex world. At worst, medical signs offer objective evidence that gives us direction.

We’ve sequenced the human genome and achieved worldwide eradication of smallpox, but physicians continue to look for the sure signs.

Modified image from Kelly Sikkema on Unsplash