Kidneys Rule Qi Grasping
kidneys grasp the qi that is inhaled through the lungs to help regulate respiratory movements. Although respiratory functions mainly depend on the lungs, inhaled qi must flow down and be grasped by kidneys for smooth respiratory movements to occur. Since normal respiration depends on mutual regulation by the kidneys and lungs, sayings such as "the lungs are the master of qi, the kidneys are the root of qi; the lungs exhale qi and the kidneys inhale qi" are commonly used to describe this relationship.
In order for the kidneys to be able to grasp the qi, they must have an abundance of stored essence and their astringent or grasping or holding functions must be intact. When a kidney deficiency develops and there is a failure to grasp the qi, the qi will not flow down to the kidneys, leading to symptoms such as difficulty inhaling, breath shortness or wheezing during motion, spontaneous perspiration, and fatigue.
Normal respiratory movement from a TCM perspective
