Welcome to NeuroTalk:
I think if you suspect low potassium for a long period of time, and you eat normally... I'd look to the kidneys. There are conditions of the kidney that waste potassium thru the urine. You can get tested for this.
Another loss can occur from the bowel. Frequent loose stools or diarrhea will cause potassium to be lost. This is because in the upper colon potassium is pumped into the bowel, and then slowly reabsorbed, as the body needs it. This mechanism levels out the blood levels, when dietary excess occurs. (not that common).
So increased loose stools will waste your potassium.
I can't really respond to the ALS question, as I am not trained in its symptomatology.
You could ask the Sjogren's question on our PN forum. Some posters there are very up on the testing etc. I do know from reading their posts that Sjogren's is very difficult to diagnose and because of this complete diagnosis is sometimes fugitive.
Our PN forum:
http://neurotalk.psychcentral.com/fo...sprune=-1&f=20
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All truths are easy to understand once they are discovered; the point is to discover them.-- Galileo Galilei
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Weezie looking at petunias 8.25.2017
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