Maybe a simple visit to the doctor and get a blood test.
I was not feeling well for 1-2 weeks, once in a while I would throw up. Thought I just had a "bug".
My friends finally talked me into seeing my doctor, they took a blood test and that afternoon the test came back.
They told me to go to the hospital now. They said I had critically low salt.
My kidneys were not functioning much, they put me on a saline drip. Kidneys improved quickly but was on the drip
from Monday afternoon till Wednesday noon. Jabbed every 4 hours for blood tests.
I eat a pretty salty diet, we are not sure yet what caused this but they stopped my water pill I was taking.
Today I went back to doctor for a follow up blood test. I was a little below the average range.
We will see what the future brings, but a simple blood test got the ball rolling to the problem.
Good luck, Brian
         side note, dang the hospital had a good open faced roast beef sandwich with mashed potatoes and gravy!