The body hangs out signs all over the place about its state of health. You just have to be able to read the signs.
So you set up an agreed system of signals with your deeper levels of knowing, your subconscious self.
These methods have been called various things over the centuries of man’s history and have often been assigned to the “magic” side of man…wrongly. It’s just that we don’t know enough about how the human being works. Knowledge is accumulating all the time in the realm of science. But for the real updates we often have to go back to OLD ESOTERIC KNOWLEDGE.