Polyuria (/ˌpɒliˈjʊəriə/) is excessive or an abnormally large production or passage of urine (greater than 2.5 L[1] or 3 L[6] over 24 hours in adults).

It may also occur after supraventricular tachycardias, during an onset of atrial fibrillation, childbirth, and the removal of an obstruction within the urinary tract.

People who produce less urine even in the presence of adequate fluid intake are probably not adapting well to high altitudes.

One study from 2008 laid out a hypothesis that hyperglycaemic and osmotic polyuria play roles ultimately in diabetic nephropathy.

According to NICE, desmopressin can be considered for nocturnal polyuria, which can be caused by diabetes mellitus,[5] if other medical treatments have failed.