By Eileen McLaughlin, RN, BSN Salt or sodium imbalance occurs when there is too little or too much sodium in the bloodstream. The condition is called hyponatremia when there is too little sodium, and hypernatremia when there is too much sodium in the bloodstream. The kidneys absorb most of the sodium in the body.
Sodium helps the kidneys to regulate water levels in the body.
Normally, the sodium-water balance in the body is regulated by the hormone aldosterone. This hormone causes the kidneys to hold onto water. When this system is out of balance, the body either gets rid of or absorbs too much sodium. A person who has the flu and uncontrollable vomiting needs to be monitored carefully. He or she may need to be admitted to a hospital to get fluids to prevent dehydration and salt imbalance.