Whipple's triad

Lore & Background

Whipple's triad dates back to the 1930s, when a few patients with hypoglycaemic symptoms due to hypoglycaemia were found to be cured by surgery to remove an insulinoma, but a large proportion of people with symptoms suggestive of hypoglycaemia apparently had no need of surgery. Diagnostic testing was rudimentary; beyond a crude assay for reducing substances as an indirect measure of blood glucose, no way had yet been found to measure hormones and metabolites such as insulin, with no imaging procedures for internal organs such as the pancreas.

Allen Whipple was a well-known surgeon who had pioneered pancreatic surgery. He proposed that no pancreatic surgery to look for insulinoma be performed unless these criteria were met. For this reason, Whipple's triad is also known as Whipple's criteria.

The use and significance of the criteria have evolved over the last century as understanding of the many forms of hypoglycaemia has increased and diagnostic tests and imaging procedures have improved. Whipple's criteria are no longer used to justify surgical exploration for an insulinoma, but to separate 'true hypoglycaemia' from a variety of other conditions in which symptoms suggestive of hypoglycaemia occur, but low glucose levels cannot be demonstrated.

Reader's Guide

Whipple's triad remains a foundational concept in the evaluation of hypoglycaemia, though its role has shifted over time. Originally proposed by surgeon Allen Whipple in the 1930s to justify exploratory pancreatic surgery for suspected insulinoma, the criteria are now invoked far more often by endocrinologists than by surgeons. The triad consists of symptoms known or likely to be caused by hypoglycaemia (such as tremor, tachycardia, anxiety, dizziness, and loss of consciousness), a low blood plasma glucose concentration measured at the time of symptoms (less than 55 mg/dL or 3.1 mmol/L), and relief of symptoms when glucose level is increased. Today, the criteria are used primarily to distinguish true hypoglycaemia from conditions like idiopathic postprandial syndrome, where symptoms occur without demonstrable low glucose. The radiological investigation of choice for insulinoma is now endoscopic and/or intraoperative ultrasonography. Whipple's triad is not exclusive to insulinoma; other conditions causing hyperinsulinism can produce the same signs.

Did You Know?

• Whipple's triad was first described by pancreatic surgeon Allen Whipple to establish criteria for exploratory pancreatic surgery to look for insulinoma.
• The essential conditions are symptoms of hypoglycaemia, low blood plasma glucose concentration, and relief of symptoms when plasma glucose concentration is increased.
• Whipple's criteria are now invoked far more often by endocrinologists than by surgeons.
• The radiological investigation of choice for insulinoma is now endoscopic and/or intraoperative ultrasonography.