Other and unspecified manifestations of thiamine deficiency

This code represents various clinical signs and symptoms resulting from insufficient thiamine (Vitamin B1) intake or absorption, excluding specific neurological (e.g., Wernicke-Korsakoff syndrome) or cardiovascular (e.g., wet beriberi) manifestations. It encompasses a range of non-specific presentations such as fatigue, irritability, muscle weakness, and gastrointestinal disturbances.

Use this code when documentation indicates a diagnosis of thiamine deficiency with symptoms that do not clearly fit into the categories of dry beriberi (neurological) or wet beriberi (cardiac). This applies to cases where the physician explicitly states "thiamine deficiency, unspecified" or describes other general manifestations. Supporting documentation should include laboratory confirmation of low thiamine levels or a clinical diagnosis based on response to thiamine supplementation.

• Do not use this code if specific neurological (e.g., polyneuropathy) or cardiac (e.g., high-output heart failure) manifestations of thiamine deficiency are documented; use more specific codes from the 265 series.
• Always review the physician's notes for the most specific diagnosis of thiamine deficiency before defaulting to this unspecified code.
• Consider sequencing this code after any underlying conditions contributing to malabsorption or malnutrition, if applicable.