The pulse can be excessive or deficient, with the interaction of yin and yang, there can be overflow or inundation, obstruction or blockage. What does this mean? When the pulse is felt before the barrier, it is the movement of yang, and the pulse should appear floating at nine parts. If it exceeds this, it is called excessive; if it is less, it is called deficient. If it reaches the fish border, it is called overflow, which is external obstruction and internal blockage, a pulse of yin overcoming. When the pulse is felt after the barrier, it is the movement of yin, and the pulse should appear sinking at one inch. If it exceeds this, it is called excessive; if it is less, it is called deficient. If it enters the chi, it is called inundation, which is internal obstruction and external blockage, a pulse of yang overcoming. Therefore, inundation and overflow are the true visceral pulses, and a person will die without being ill.