What are the three main signs of diabetes?
The three main signs of diabetes mellitus are called as the diabetic triad: polyuria, polydipsia and polyphagia.
Polyuria is the excessive elimination of urine; in diabetes it is caused by decreased water resorption in the renal tubules because of increased osmolarity of the glomerular filtrate (caused by excessive glucose). Polydipsia is the exaggerated ingestion of water; the thirst is due to the excessive water loss in the urine. Polyphagia is the exaggerated ingestion of food caused by deficiency in energy generation by glucose-lacking cells.