That's a pretty rare condition in the US. I'm going to assume that you eat a healthy diet instead of the typical US diet that contains over a thousand milligrams more than the highest that we should be eating.

We do use more when hiking though, especially when in warm and hot weather, and the sodium (mostly, but the other electrolytes are needed as well) is needed for the body to absorb the water.

Add some sodium and probably a little potassium to your hiking diet. Just don't go overboard. Some Gatorade drink mix or equivalent added to your water should be enough. Nunn sport tablets are good too, but have less sodium so maybe not enough if you're sweating profusely. It's also not the best tasting (the grape at least, I haven't tried other flavors yet), but the taste can be acquired and tolerated.