Traditional Chinese Medicine (TCM) Roots: The concept of 火 (huǒ) as “internal heat” is central to Traditional Chinese Medicine. Strong emotions, especially anger, are believed to generate “liver fire” (肝火, gānhuǒ). When someone has too much of this internal fire, they might become irritable, short-tempered, and easily angered. So, when a person says they are 火大, they are tapping into a deep-seated cultural understanding of anger as a physiological imbalance of “fire.” This is related to the common concept of
上火 (shànghuǒ), “to have excess internal heat,” which can manifest in physical symptoms like a sore throat or mouth sores, as well as irritability.