Thyrotoxicosis factitia with thyrotoxic crisis or storm

This code describes a severe and life-threatening exacerbation of hyperthyroidism, specifically when it is caused by the intentional or unintentional ingestion of excessive thyroid hormone medication. It represents a state of extreme thyrotoxicosis leading to systemic decompensation, often characterized by fever, tachycardia, altered mental status, and multi-organ dysfunction.

Apply this code when documentation clearly indicates a patient experiencing a thyrotoxic crisis or storm that is directly attributable to exogenous thyroid hormone intake. This typically occurs in patients with a history of thyroid hormone replacement therapy or those misusing thyroid medications. Supporting documentation should detail the acute, severe symptoms consistent with a storm and the etiology of factitious thyrotoxicosis.

• Distinguish from other causes of thyrotoxic crisis (e.g., Graves' disease, toxic nodular goiter) which have different codes.
• Ensure documentation explicitly states "crisis" or "storm" and links it to exogenous thyroid hormone.
• Code any associated symptoms or complications (e.g., atrial fibrillation, heart failure) as secondary diagnoses.