On some exotic urine colors in ancient and Byzantine Greek literature.

This work does not analyze the entire subject of uroscopy but focuses on a very small part thereof: i.e., some rare urine colors, in particular green and blue. These are so rare that most modern nephrologists have never encountered them. We conducted a small survey comparing contemporary knowledge with that of the past, with the participation of 40 Greek nephrologists (25 juniors and 15 seniors). Of these, 63% rejected the notion that green or blue urine even exists, while of those who were aware of them, only 20% had personally encountered them. According to our search of the modern literature, such colors result from either consumption of green or blue pigments, liver dysfunction or urine infection by certain bacteria. We searched and traced several passages on these rare urine colors, referred to in ancient Greek fewer than 7 different names, in the Greek medical literature of the Classical, Roman and Byzantine eras. In these passages, the authors not only gave detailed descriptions of the medical conditions of the corresponding patients but also explained this appearance of the urine. Surprisingly, in the studied texts we also found identical explanations with those in modern texts: consumption of certain foods, liver disease and inflammation. We present and comment on these passages, concluding that many uroscopical findings of antiquity were not quackery, but rather reliable medical statements based on thorough observation and rational reasoning.