Jaundice or icterus (derived from the ancient Greek word ikteros that described the yellow-breasted oriole bird) is not a diagnosis in itself but constitutes one of the major signs in medicine. Jaundice refers to the yellowish discoloration of tissue that occurs as a consequence of the deposition of bilirubin. This discoloration is a physical manifestation of a marked increase in serum bilirubin levels. Normal serum bilirubin values are <17 μmol/L; for jaundice to be perceived visually serum bilirubin levels need to be elevated to >40 μmol/L (equivalent to 2.5 mg/dL).1
Most serum bilirubin is formed from the breakdown of the haem contained in senescent red blood cells by the reticuloendothelial system. Thus, unconjugated bilirubin is released in the bloodstream, where it is bound by albumin. Through the blood circulation bilirubin is moved to liver hepatocytes, where it undergoes further processing. In brief, bilirubin becomes conjugated in the hepatocytes through glucuronidation, which allows it to be excreted from the body (unconjugated bilirubin is water insoluble and cannot pass into the urine). Conjugated bilirubin forms one of the main components of bile and most of it passes through the biliary tree to the intestine. Unconjugated and conjugated bilirubin are reported in laboratory measurements as indirect and direct bilirubin, according to their chemical properties (i.e. reaction with reagents).1
Jaundice can be caused by abnormalities in any of the steps comprising the formation, metabolism and excretion of bilirubin. In addition, these processes may be functioning properly, but jaundice can be seen because of an obstruction of the biliary tree at any point, from its intrahepatic origins to its end at the ampulla of Vater. For this reason, it is clear that numerous conditions can result in jaundice. When faced with a patient presenting with jaundice a reasonable and careful diagnostic approach is, therefore, warranted to elucidate the underlying cause of this sign. Conventional wisdom may be that “jaundice by itself never killed anyone,” but it is imperative to find the cause as soon as possible, as prompt intervention saves lives in many cases.
Here, we outline several of the mistakes made when approaching a patient presenting with acute jaundice based on our clinical experience and published data.