Disease is....

In the light of Yin-Yang theory, when our body get a disease, it is mainly caused by an imbalance between Yin and Yang within our body. Though it looks simple, but it is quite complicated, however in general, there are two categories of imbalance, which is  relative predominance yin or yang, and relative decline of yin or yang.

Relative predominance of yin-yang means that our body get excess of yin or yang because of invasion of pathogenic factors which cause imbalance of yin-yang within our body. For an example, the invasion of bacteria which cause throat infection and bring high fever, reddish complexion etc, is categorize as an excess of predominance yang. In time, the excess of yang factor, will consume body fluid and cause us to thirst more than usual, scanty urine and constipation. Therefore, because of predominance of yang consume body fluid, the relative predominance of yang is said to caused the disease of yin.

Then, relative predominance of yin means that our body get invasion of pathogenic thing in yin nature. The best example of this is common cold. In common cold, our body get excess of yin, which bring a disease of yang. So, when yin pathogenic nature invade, it will bring  cold symptoms such as aversion to cold, cold limbs and cold abdominal pain also yang-deficiency syndrome such as whitish complexion, lassitude, frequent lying on bed, slow and weak pulse.

Instead of get excess as in relative predominance of yin-yang, the relative decline of yin-yang,is a condition of impairment because of the yin or yang factor within our body decline below normal level. Consequently bring associated syndrome to our body. It is said that " deficiency of yang leading to cold" and "deficiency of yin leading to heat"  to show how a decline in yang will bring cold because of inability of yang to restrain the yin within and a decline of yin will bring fever, night sweating, etc, because of inability of yin to restrain the yang within.

After all, the yin cannot exist without the yang, and yang cannot exist without the yin, therefore when a disease develop morbidly and cause a condition known as "loss of yin" or "loss of yang"  death may occur as yin and yang separated.