Chinese mythology, folktales, and literature
Mencius said: “Even Xi Shi – the most beautiful woman of all – if covered in filth, would make everyone cover their noses and walk away. Yet even a morally flawed person, if he fasts, purifies himself through ritual bathing, and cleanses his heart, may offer sacrifices to the Heaven.”
Because Xi Shi, the famous beauty, suffered from heartburn, she would often frown in front of all the neighbours.