Hyposmolality and/or hyponatremia

This code describes a condition characterized by abnormally low osmolality of the blood, often accompanied by a reduced concentration of sodium in the bloodstream. It indicates an imbalance in the body's fluid and electrolyte regulation, where there is an excess of water relative to solutes.

Use this code when documentation specifies hyposmolality, hyponatremia, or both, as a primary diagnosis or a significant co-morbidity. Common scenarios include syndrome of inappropriate antidiuretic hormone (SIADH), excessive water intake, or certain kidney disorders. Documentation should clearly state the laboratory findings confirming low serum sodium and/or osmolality.

• Always look for specific causes of hyponatremia (e.g., SIADH, diuretic use) and code them additionally if documented.
• Distinguish between acute and chronic hyponatremia if specified, as this may impact treatment and further coding.
• Do not use this code if the hyponatremia is iatrogenic and a more specific code for the adverse effect of a drug is available.