Hi Dr Stephen. I was wondering,,what would cause low potassium levels in a patient? My sister was brought to the E.R 2 days ago, because she was having hallucinations. Seeing things,people that were not there. Mental illness runs in our family. Bi-polar, depression etc. She also is an alcoholic. I m thinking it is the alcohol causing it,,yet she claims to not be drinking any more. I suspect I am right on here!! Thank you!!