Are polyuria and diuresis different, and if so, how?

Question

Polyuria - Wikipedia states:

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). Increased production and passage of urine may also be termed as diuresis.

whereas Diuresis - Wikipedia states:

Diuresis (/ˌdaɪjʊˈriːsɪs/) is the excretion of urine, especially when excessive (polyuria). The term collectively denotes the physiologic processes underpinning increased urine production by the kidneys during maintenance of fluid balance.

These are incredibly similar definitions, which even appear to reference each other. Can anyone here provide any clarification?

Answer 1

The definitions are similar (or depending upon the source essentially the same as in polyuria vs diuresis). One is a symptom of disease. The other is an effect of an intervention, usually related to natriuresis. Diuretics are drugs that increase the flow of urine. Kehrenberg, et. al.

What is lost in many of the definitions, except for the one cited above, is that as a physician I would use the term "polyuria" in the history of present illness or review of systems if the patient is reporting spontaneous symptoms. I would use the term "diuresis" if the patient was receiving substances that intentionally and directly caused the increase in urine volume, such as furosemide, acetazolamide, mannitol, etc. On the other hand, a diabetic on prednisone with a glucose of 600 and reporting urinating excessively would typically be described as "polyuria" in the HPI/ ROS but in the medical decision-making we would describe it as "osmotic diuresis due to hyperglycemia, as an adverse effect of the prednisone."

This is an "art of medicine" issue, and it is plausible that a nephrologist may have a slightly different opinion.