If the blood sugar is too high, the kidneys cannot reabsorb fluid. Therefore, the body, trying to equalize the glucose concentration in the blood and in the cells, dissolves blood with intracellular fluid, thus bringing the concentration of glucose to normal. This results in frequent urination.
Dry mouth, excessive thirst
A dry mouth and strong thirst are responses to severe fluid loss. The hypothalamus, which assesses the level of dehydration and causes thirst, sends a corresponding signal to the brain. Of course, you cannot refuse to drink, but it’s better if you choose water or tea without sugar.