PUZZLE:
A patient came in with urinary frequency & urgency.
Here is the urinalysis.

What do you suspect as the underlying cause?

(I will show the answer after a dozen or so replies.)

Thanks so much for very smart answers, everybody, quickly passing one dozen.

This patient wears a mask many hours per day. Here's what happened to the urine.

Obstructed air flow keeps more carbon dioxide for extended time in masked airspace --> more carbon dioxide in lungs -->

More carbon dioxide in lungs (hypercapnia) --> lowers pH -->
increasing acid condition (respiratory acidosis) overwhelms compensatory mechanisms of the body --> The kidneys now have the hard job of . . .

The kidneys now have the hard job of dumping acid. How do the kidneys get rid of bad stuff? Excrete that acid in the urine. --> Urinalysis shows very low pH, bottom of the chart: pH = 5.0. That's about as acid as coffee. Which is fine for coffee, but . . .

But not so great for urine, which reflects what got taken from blood (remembering that kidneys' main job is to clean the blood, by excreting less than ideal substances into urine for disposal).

So the moral of the story is . . .