Hyponatremia is usually identified through basic metabolic panel testing. It may appear in patients with heart failure, kidney disease, liver disorders, endocrine conditions, or those taking certain medications like diuretics. Symptoms can range from mild fatigue and headache to confusion, seizures, or coma in severe cases.
From a coding standpoint, hyponatremia may be the primary diagnosis or a secondary condition that impacts treatment decisions and length of stay. Clear provider documentation is the foundation for correct code selection.
What Is ICD 10 Code for Hyponatremia?
The ICD 10 code used for hyponatremia is E87.1. This code represents hypo-osmolality and hyponatremia and is used when low sodium levels are clinically significant and documented by the provider.
E87.1 should be assigned when laboratory findings confirm low sodium and the provider includes hyponatremia in the assessment or plan. It can be reported as a primary or secondary diagnosis depending on the clinical scenario.
Related ICD 10 Codes for Hyponatremia
In some cases, additional or alternative codes may apply based on the underlying cause or associated electrolyte imbalance. E87.0 is used for hyperosmolality and hypernatremia and should not be confused with hyponatremia. E86.0 may be used for dehydration if documented separately and supported by clinical findings. Codes related to underlying conditions such as heart failure, chronic kidney disease, or SIADH should be reported in addition to E87.1 when documented.
Selecting related codes requires careful review of provider notes to avoid overcoding or assumptions.
Services Are Covered Under the Hyponatremia ICD 10 Code
The ICD 10 code E87.1 supports a wide range of medically necessary services. These include laboratory testing such as basic and comprehensive metabolic panels, serum osmolality tests, and urine sodium studies. It also supports inpatient monitoring, IV fluid management, electrolyte correction, medication adjustments, and specialist consultations when clinically indicated.
Coverage is ultimately determined by payer policies, but accurate coding helps justify the need for evaluation and treatment related to sodium imbalance.
Coding History of Hyponatremia
Hyponatremia was previously coded under ICD 9 as 276.1. With the transition to ICD 10, E87.1 was introduced to provide more clinical clarity by combining hypo-osmolality and hyponatremia under one code. This change improved data reporting and allowed better tracking of electrolyte disorders across healthcare systems.
How to Use the ICD 10 Code for Hyponatremia Correctly
E87.1 should only be reported when hyponatremia is clearly documented by the provider. Lab values alone are not enough for code assignment. The condition must be addressed in the assessment, plan, or treatment notes. When hyponatremia is due to another condition, both codes should be reported unless documentation states otherwise.
The code should not be used for borderline or clinically insignificant sodium changes unless the provider identifies it as a condition requiring care.
Included Under ICD 10 Code E87.1
ICD 10 code E87.1 includes acute and chronic hyponatremia when associated with low serum sodium and low plasma osmolality. It also includes cases where hyponatremia impacts clinical management, monitoring, or treatment decisions.
This code is appropriate in hospital, emergency, and outpatient settings when supported by documentation.
Excluded From ICD 10 Code E87.1
E87.1 excludes hypernatremia and conditions involving high serum sodium. It also excludes electrolyte abnormalities that are transient and not clinically addressed by the provider. Conditions such as dehydration or fluid overload should not be bundled into this code unless specifically linked and documented.
Following includes and excludes guidelines helps reduce audit risk and ensures coding accuracy.
