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The History of Total Bilirubin

Jaundice, the yellowing of skin and eyes this test ultimately explains, was recognized as a medical condition long before anyone understood its underlying chemistry — the ancient Greek physician Hippocrates described the connection between liver problems and yellow skin more than two thousand years ago, though many centuries would pass before scientists ever identified bilirubin as the actual pigment responsible for that visible color change in the skin. That chemical understanding finally arrived in 1913, when Dutch physician A.A. Hijmans van den Bergh developed a reliable chemical reaction for measuring bilirubin directly in blood, giving physicians their first genuinely quantitative alternative to simply eyeballing how yellow a patient's skin appeared during a routine physical examination at the bedside, without any real instrumentation available at all at that time.

What Total Bilirubin Actually Is

Total bilirubin is simply the sum of the two forms of this pigment circulating in blood: the unprocessed, water-insoluble form released when red blood cells break down, and the water-soluble form the liver produces afterward specifically for excretion into bile and eventually the intestine. Reporting the total value gives physicians an immediate, big-picture sense of whether bilirubin is building up in the bloodstream at all, before they even need to determine which specific form is responsible or precisely why that buildup is happening in the first place at all. This makes total bilirubin especially useful as a fast first screening test, particularly in newborns, whose livers are often still too immature to process bilirubin efficiently during the first several days of life outside the womb, when levels can rise quickly and rather unpredictably.

How Total Bilirubin Is Measured

Laboratories measure total bilirubin using van den Bergh's original diazo chemistry, adding an accelerant chemical such as caffeine-benzoate to a blood sample so that both the water-soluble and water-insoluble forms react fully with the test reagent, producing a colored compound whose intensity is measured precisely using a spectrophotometer under standard laboratory conditions each and every single time. This combined result can then be compared against a separately measured direct bilirubin value to calculate exactly how much of the total comes from each individual form, giving doctors a considerably fuller diagnostic picture from just a single blood draw taken once during a visit.

Scientists Behind the Science

Hippocrates's ancient clinical observations gave physicians their earliest conceptual link between liver disease and visible yellowing of the body, an association that held up for over two thousand years before its underlying chemistry was ever properly explained by modern science. A.A. Hijmans van den Bergh's 1913 chemical breakthrough finally turned that ancient observation into a precise, quantifiable laboratory value doctors could actually track reliably over time. Decades later, in 1958, British pediatrician Richard Cremer made a serendipitous discovery while observing premature infants in a hospital nursery: sunlight exposure appeared to visibly lower their bilirubin levels, a chance finding that led directly to the modern phototherapy treatment still used to protect vulnerable newborns from dangerously high bilirubin today, in hospitals worldwide, every single day of the year.