My guess is you need more potassium and more salt. Try adding extra salt to food (or salt pills like below) and take this potassium.
http://astore.amazon.com/marisnutran05-20/detail/B001AWSR8E
Salt:
http://astore.amazon.com/marisnutran05-20/detail/B002IY96B0
Also make sure to get 1/2 your body weight in ounces of water a day (so if 150 pounds, 75 ounces of water minimum).