ICD-10 Code G90 – Disorders of autonomic nervous system (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code G90 – Disorders of autonomic nervous system
What it is
G90 describes disorders affecting the autonomic nervous system, which controls involuntary body functions such as heart rate, blood pressure, digestion, and sweating. Use it when the record documents an autonomic nervous system disorder without a more specific diagnosis.
Clinical signs
Clinical features vary; refer to documentation. Commonly reported findings may include abnormal blood pressure regulation, heart rate changes, sweating abnormalities, or other involuntary function problems tied to autonomic dysfunction.
When to use this code
Use G90 when the provider identifies a disorder of the autonomic nervous system and does not specify a more detailed subtype. It is appropriate for nonspecific autonomic dysfunction when the documentation supports the diagnosis. If the record names a more precise condition, code that instead.
Do not use for
Do not use this code for unrelated neurologic, cardiovascular, or endocrine conditions that only cause similar symptoms. Check documentation if the chart describes a specific autonomic disorder or another primary diagnosis.
Coding tip
Confirm the provider explicitly links the symptoms to autonomic nervous system dysfunction before assigning G90.