In Chinese medicine, somnolence or fatigue is due to some dysfunction of the spleen, lungs, and/or kidneys. These are the three viscera in Chinese medicine which engender and transform the qi, and wakefulness is a function of the qi. If there is abundant qi and that qi is unobscured, then the person is wide awake, has abundant energy, and their mind is clear. In particular, the spleen is the so-called latter heaven root of the engenderment and transformation of
qi. Therefore, according to Chinese medical theory, in clinical practice, all fatigue or somnolence involves some degree of spleen vacuity.
