Polydipsia is possible to rule out psychogenic polydipsia or habit polydipsia. Polydipsia is a symptom (evidence of a disease state), not a disease in itself. As it is often accompanied by polyuria, investigations directed at diagnosing diabetes insipidus and diabetes mellitus can be useful. Blood serum tests can also provide useful information about the osmolality of the body's extracellular fluids. A decrease in osmolality caused by excess water intake will decrease the serum concentration of red blood cells, blood urea nitrogen (BUN), and sodium. Polydipsia Polydipsia is excessive thirst or excess drinking. The word derives from the Greek () "very thirsty",
Caduceus as a symbol of medicine college, had carried before him a silver caduceus on a cushion, and later presented this artefact to the college, where it remains in the College's possession. This use was adduced by the medical historian (and primary apologist for the use of the caduceus in a medical context) Fielding Garrison to support his argument that the caduceus was used as a symbol of medicine as far back as the 16th century. However, as Walter Friedlander noted, "what Caius used was a non-specific herald's wand, rather than the caduceus of Hermes." In support of this assertion he quotes Caius's own words on