Low potassium isnt something you should disregard at all. If it were to get low enough, it can have pretty bad consequences. It can explain memory problems and brain fog, it also can affect your heart. It can cause irregular rhythems, fast heart rate, a fluttery feeling. Fatigue is also very prominant. I had recently had some severe memory problems and irregular heart beats and sometimes it felt like my heart actually stopped for a brief period after attacks. My memory got so bad that I couldnt remember anything, I would find myself somewhere and have no idea why, I forgot how to do things, such as I forgot how to use the sink, I could not figure out hot and cold, even after testing each because I would forget before I could use it. That last for nearly a week and finally got a handle on it. Thats just an example. I never really said anything to my doctor though. And during a recent hospitalization they announced my low potassium, and since working on treatment I can say things have gotton better. In any case, if you do a search on low potassium you will find many more symptoms than I have listed here, it can cause a lot of things, some really odd too. Just keep in mind that potassium is one of the factors that keep your heart working properly, and strong, thats why the OJ commercials always advertise it for a healthy heart. Eating a lot of bananas, OJ, and dark green veggies can also be benficial, I do mean lots too.
My doctor chose to let me try changing my diet first, and it helped me alot. He said that pottasium supplements can be harsh on your stomache and cause other side effect he didnt mention. But try to keep it in order and don let it get out of hand, its actually quite improtant for your overall health.