Hippocrates, Aristotle and the ancient Egyptians inferred diagnoses from urine evaluation, but it was not until the Middle Ages that uroscopy reached diagnostic dominance. A major reason for its rise to prominence was the publication of Johannes de Ketham’s Fasciculus medicinae in 1491.1 This was the first illustrated medical book printed and is also among the most beautiful of such texts. The importance it places on urine evaluation is evident on page 1b, which depicts a urine wheel: a large circle surrounded by 21 thin-necked, urine-filled flasks (matulae) (Box 1). This wheel shows how the colour and consistency of urine could be matched to a diagnosis. Disease was thought to result from the imbalance of humours, reflected by urine colour. In the corners of the urine wheel, four small circles contain descriptions of the four temperaments: sanguineous, choleric, phlegmatic and melancholic.

In an era nearly four centuries earlier than Laënnec’s stethoscope, three centuries before the first investigations into blood pressure and two centuries earlier than Hooke’s microscope, uroscopy became the most important tool in evaluating internal health of the human body — more highly valued than the pulse. Its use is depicted by a woodcut from the first Italian edition of de Ketham’s Fasciculus medicinae, showing a professor teaching diagnosis by uroscopy as different matulae are presented to him (Box 2). Although modern technology allows greater insight into the hidden clues of bodily functions, visual observation of urine is still useful. A contemporary urine wheel with diagnoses that might be associated with visually abnormal urine is presented in Box 3.

1 Urine wheel from the first edition of Fasciculus medicinae*

* An English translation of de Ketham’s urine wheel is available at www.mhm.ku.dk/upload/urinposter.pdf.2

2 Professor teaching diagnosis by uroscopy

3 A modern-day urine wheel that contrasts de Ketham’s diagnoses (italics) with modern interpretations of urine appearance