Hypo-osmolality and hyponatremia

This code signifies a state where the body's fluid concentration is abnormally low (hypo-osmolality) and there is a reduced sodium level in the blood (hyponatremia). This imbalance can affect cellular function and lead to various neurological and systemic symptoms.

Apply this code when documentation explicitly states both hypo-osmolality and hyponatremia are present. This often occurs in conditions like excessive water intake, certain kidney diseases, or medication side effects. Supporting documentation should include laboratory results confirming low serum osmolality and sodium levels.

• Remember the Excludes1 note: Do not code this with E22.2 (SIADH), as SIADH is a specific cause of hyponatremia.
• Always look for the underlying cause of the hypo-osmolality and hyponatremia, and code it as a primary diagnosis if appropriate, with this code as a secondary.
• Ensure the documentation clearly distinguishes between true hypo-osmolality and pseudohyponatremia, which is not coded here.