# Hyponatremia --- **Hyponatremia** is a condition where there is a dangerously low concentration of [[sodium|sodium ions]] in the blood. Sodium is a very important extracellular ion that helps maintain blood [[osmosis|osmolarity]] (too little makes the blood *hypo*tonic) and also facilitates neuronal [[action potential|neuronal conduction]], so the signs and symptoms of hyponatremia manifest as problems with the CNS or with fluid imbalances. Dilutional hyponatremia is a form of hyponatremia where there maybe be an overall sufficient amount of sodium in the body, but a [[fluid volume excess]] which causes the *relative* balance to be hyponatremic. ## Causes Generally speaking Americans take in *plenty* of sodium in our diets, this generally only happens during endurance activities after excessive sweating, or by drinking too much fluids and causing **dilutional hyponatremia** where there is too much fluid intake and not enough sodium intake to go along with it. Other causes are: - [[Addison's disease|adrenal insufficiency]] - this means there isn't enough aldosterone, which means Na+ is lost in the urine - some medications - anticonvulsants - SSRIs - water retention, causing dilutional hyponatremia - [[heart failure]], liver failure, kidney failure - [[SIADH]] ## Signs & Symptoms Hyponatremia can cause [[dizziness]], [[fatigue]], [[nausea]], [[emesis|vomiting]] and [[muscle cramps]], and can even cause [[seizures]], [[coma]] or [[death]] if left untreated. - [[seizures|seizures/status epilepticus]] - very dangerous - altered mental status - lethargy, confusion, etc. - increased risk of cerebral edema - fluids are leaking out into the tissues. - can even cause brain herniation - brain pushing through the foramen magnum - coma - nerves and muscles also depend on sodium - cramps, or weakened muscles - spasms - the diaphragm is a muscle, we might see shallow respirations - nausea/vomiting - orthostatic hypotension - perhaps we'll see some things related to [[fluid volume deficit|hypovolemia]] ## Treatment Treat underlying condition, usually with PO sodium. PO is best, but if worse comes to worse you can use LR, NS. (Remember not to do it too fast). Also, sometimes free water restriction is called for. ## Nursing Considerations When you think hyponatremia, think neuro. - I/Os - daily weights - much more accurate than I/Os - thorough history - establish links to current illnesses - their meds - monitor for CNS changes - monitor serum sodium - educate and assist ___