Using the Five Phases to explain the mother-child relationship among the five zang-organs, it is referred to as the child depleting the mother due to illness. This is often used to elucidate the pathological interactions of deficiency diseases among the five zang-organs.

For example, earth generates metal, where the spleen (earth) is the mother and the lung (metal) is the child. When lung qi deficiency progresses to a certain extent, it may affect the spleen qi's transformative function.