I don't there can be much doubt that improper ratios of sodium in the body can be bad. In particular I'd look at the ratio of sodium to potassium. But the same goes the other way too. Being sodium-deficient is really not fun. I know from experience.

Sodium and potassium have a significant number of important roles in the body and they are balanced against eachother. Too much sodium will mess up the potassium functions and vice versa.