Haemoglobinuria

Part of speech: noun

Definitions

1. The condition in which hemoglobin released from destroyed red blood cells appears in the urine, giving it a dark or reddish colour
2. A medical sign where free red blood pigment passes into the urine because red cells have broken apart within the bloodstream
3. Abnormal presence of the oxygen-carrying blood protein in urine, usually caused by hemolysis of red blood cells in the body

Etymology: Haemoglobinuria is a compound built from two parts that were each coined in the modern era. The first element, "haemoglobin," combines "haem," from Greek "haima" meaning blood, with "globin," a term for the protein portion of the molecule, and it names the oxygen-carrying pigment in red blood cells. The second element, "-uria," comes from Greek "ouron," meaning urine, and appears in many medical terms for substances found in urine. Put together, the word describes the presence of free haemoglobin in the urine, which occurs when red blood cells break apart inside the body and release their contents. The word is therefore a technical coinage rather than an ancient one. Greek writers had no concept of haemoglobin as a molecule, so the term reflects the chemistry that medicine developed in the nineteenth and twentieth centuries, when the pigment was identified and named. Its structure is simple once the parts are known: a familiar compound pattern, with classical roots supplying the precision.