《黄帝内经·灵枢·五乱》
气乱于心，可见心中烦闷，沉默不言，低头静伏而不欲动。
故气乱于心，则烦心密嘿，俛首静伏。
If the qi is disrupted in the heart, it can be seen in the form of a feeling of distress in the heart, accompanied by silence, a lowered head, and a quiet and unmotivated demeanor.