Physiological description for archaic technique of diabetes

Question

In ancient Greece the father of Medicine, Hypocrates, explained a way of diagnosing diabetes mellitus by examining the patient's urine. Explain that what is the physiological description for this archaic technique?

Answer 1

Under general conditions the glucose filtered by the renal glomeruli is approximately completely resorbed in the nephron tubules and not excreted in urine. Amid elevated glucose blood level the renal tubules can’t resorb all the filtered glucose and some quantity of the matter appears in the urine. This quantity is enough to give the sweet flavour that helped Hypocrates to identify diabetes and to distinguish it from other diseases accompanied by polyuria. Nowadays the process is inconceivable due to the danger of contamination of the tester by disease agents perhaps present in the patient's urine.