Bian Que, a famous doctor in the Spring and Autumn Period and the Warring States Period, once said:

There are six types of diseases that cannot be cured: arrogance and irresponsibility, which cannot be cured; neglecting one's body and wealth, and two failings; not being able to eat and drink properly. The third is incurable; the yin and yang are combined, the stored Qi is unstable, the fourth is incurable; the body is too weak to take medicine, the fifth is incurable, and the sixth is incurable: belief in witchcraft but not medicine. If there is this one, it will be serious and difficult to treat. _"Biography of Bian Quecang Gong"