OK, polyuria may result from being hyperthyroid. I am not diabetic, but may have partial diabetes insipidus
(according to a water deprivation test, and low ADH). Because I have hyperparathyroidism, my ionized Ca is too high at least part of the time. In hyperparathyroidism the kidneys cannot conserve water, because of incorrect functioning of ADH, although it were present. Maybe hypercalcemia, caused by any reason, can cause water loss. Those who are hyperthyroid may have slight hypercalcemia.