I recently found out that it's possible to get water retention when your sodium is low. It's called euvolemic hyponatremia and it's due to the secretion of a hormone called vasopressin or ADH (antidiuretic hormone).
Last weekend I was getting puffy and bloated, so I thought I might be eating too much salt and stopped drinking water with Sea Salt every morning. After two or three days I got even more bloated and puffy everywhere, extremely tired, restless, slightly nauseous, started having pain in all the joints, muscles and bones (especially below the knee), got so confused and disoriented that I almost wanted to call 911 because I was afraid I would just pass out and nobody was home.
Finally after looking up online about the hyponatremia symptoms I decided to take some Sea Salt and see if it gets worse or better. After about an hour all the symptoms subsided and I got much better.
Somehow it didn't make sense to me that I could have low sodium because I always put lots of salt on my food and on that particular morning my blood pressure was kinda high for me (105/55). Later I read that the low diastolic number could signal that aldosterone is low. Also vasopressin is released in order to raise the blood pressure when sodium becomes too low. So it's all backwards in terms of symptoms: your BP goes high and you hold water but meanwhile your total body sodium gets even lower because it becomes diluted. Very strange mechanism in my opinion...
What are your symptoms associated with electrolyte imbalance particularly sodium?...
Do you ever get something that extreme?
How much salt are you taking per day including food?
Do you know anything about vasopressin in the context of low adrenal function?