It is a pathological change belonging to the combination of qi deficiency and the failure of qi to ascend and lift, characterized mainly by qi deficiency and sinking. It is primarily caused by congenital insufficiency, prolonged illness leading to physical weakness, aging and physical decline, dietary injury, and excessive fatigue. It is particularly prone to occur in cases of chronic diarrhea, excessive childbirth in women, and lack of postpartum care.

Qi sinking is most closely related to the spleen. The spleen resides in the middle energizer, and its qi is responsible for ascending. When spleen qi is impaired and its lifting ability is weakened, it leads to qi deficiency and sinking. Clinically, in addition to the common symptoms of qi deficiency such as dizziness, fatigue, pale complexion, pale tongue, and weak pulse, there are also symptoms of internal organ prolapse, such as abdominal distension, gastroptosis, nephroptosis, prolapse of the rectum, or prolapse of the uterus. When the middle qi sinks and the spleen and stomach's transportation and transformation functions are impaired, it manifests as reduced appetite, abdominal distension and fullness, rectal prolapse, and diarrhea. As stated in the "Suwen-Yinyang Yingxiang Da Lun" , "When the clearing qi aspect is below, it leads to chronic diarrhea," which refers to the pathological change of middle qi weakness, failure to ascend, and the sinking of clear yang qi.