In the priestly doctrine of the ancient Egyptians, as well as in the Eastern tradition, two basic energy flows "Yin and Yang" ("Ba & Ka" in Egyptian culture) were the two constituent elements of the human being, its vital energy sources. Exactly this display lots of statues of pharaohs holding two vessels, symbolizing the "Ba-Ka" energy flows.
With the harmonious interaction of these two elements, the vital functions of the body are flowing without disturbances.
However, over time the human system requires debugging: stress, infections, electromagnetic radiation, solar activity, and other harmful factors disturb the balance of life forces.