The symptoms of electrolyte imbalance can be fairly subtle to begin with, especially if the levels aren’t out by all that much, and they’re many and varied. First look out for twitching muscles and cramps, because electrolytes are involved in muscular contraction and relaxation, and imbalances in both sodium and magnesium seem to be implicated in people getting twitchy muscles or muscle cramps. Another sign is if you are unduly fatigued and lethargic, and sometimes if your fluid balance is out of whack that can cause headaches.
But in general, it would be feeling out of sorts, but not necessarily able to put your finger on it. It’s not one of those things where there are always clear-cut symptoms, and quite often people find out that they have electrolyte imbalances, which could have been going on for a long time, by having a blood test for a general check-up.
With athletes, the one that tends to get out of whack is sodium because that’s the predominant electrolyte in your sweat. And if you get a short-term, acute sodium imbalance through losing a lot of sweat through exercise, the symptoms might be a lot more severe than someone who’s become a little bit depleted over a number of days or weeks.