Deficiency: When there's a lack or insufficiency in some aspect of the body and its functions, it can make one feel weak or tired. Eg: Digestive deficiency means a weakened digestive system, or Qi deficiency means a lack of energy. Excess is about having too much of a particular element.. Think of it as the body's way of saying "it's more than it should be," which can lead to various imbalances or health concerns. Eg: Excess Heat is often behind inflammation in the body.