Hypokalemia is an abnormally low potassium blood level.
Hyperkalemia an elevated potassium blood level, also can impair the function of skeletal muscles, the nervous system, and the heart.
Hyponatremia is a lower-than-normal concentration of sodium, usually associated with excess water accumulation in the body, which dilutes the sodium.
Hypernatremia is an abnormal increase of blood sodium. It can result from water loss from the blood, resulting in the hemoconcentration of all blood constituents.