Normal 261 – 280 mOsm/kg Indications Monitor: Electrolyte balance Acid-Base balance Hydration Evaluate function of antidiuretic hormone.   Description Osmolality is a measure of the particles in solution. The size, shape, and charge of the particles do not impact the osmolality   What would cause increased levels? Dehydration Azotemia Hypercalcemia Hyperglycemic Hyperosmolar Nonketotic State (HHNS) Hypernatremia Diabetes Insipidus Hyperglycemia Mannitol therapy Uremia Severe pyelonephritis Shock Ketosis   What would cause decreased levels? Hyponatremia Syndrome of Inappropriate Antidiuretic Hormone (SIADH) Overhydration