I’m still very curious after this many years in practice. I Google stuff all the time. A couple of times I have scratched my head about patients of mine with low potassium in the emergency room. I even had that myself in one of my very rare visits to that kind of place. I did not enjoy the flavor of my oral potassium replacement.
This abnormality turned up again the other day, and I finally stopped in my tracks and said to the patient, “I often see this happening when my patients go to the emergency room, but after a little while it normalizes most of the time. It has to be some sort of stress reaction. But we will check your level again just to make sure”.
When I Googled it, everything fell into place. All the stress hormones lower potassium. It’s not their major effect or reason to exist, but that’s how it works. I don’t know if it serves any bigger purpose. But we should definitely not assume that patients under stress with low potassium need lifelong replacement therapy.
A Country Doctor Writes: 
This happened to me. No answer was offered. But this happened when I was under a great deal of stress death of my husband being one of the events in my life. Thank you. Barbara Joy