======Hyponatremia======

  * If serum Osm > 290
    * Hyperglycemia
    * Advanced renal failure
  * If serum Osm < 290
    * If urine Osm < 100
        * Polydispia
        * Beer potomania
    * If urine Osm > 100
        * Urine Na > 25
            * SIADH
            * Adrenal insufficiency
            * Hypothyroidism
        * Urine Na < 25
            * Volume depletion
            * CHF
            * Cirrhosis