The principle of Tibetan Medicine is that whatever is beneficial is medicine, and whatever makes you unhappy and causes problems is disease.
All the diseases that we experience in our bodies have a condition and a cause. There are four conditions: unbalanced weather, unbalanced food, behavior of the body, and bacteria. It is these four conditions that make unmanifested disease manifest. We say all diseases are first unmanifested because the qualities of disease already exist in the body; it is the four conditions that make the disease manifest.
There are three causes of disease: ignorance, attachment and anger. We always have all three of these emotions unmanifested. When they manifest, they cause physical disease. Also, when physical diseases manifest, they manifest mental diseases, which are these three emotions. Therefore, body and mind are interdependent; they affect each other. When one goes wrong this affects the other. When the mind is out of balance this infects the body, and vice-versa. In addition, if the external conditions—the four conditions mentioned above—come out of balance, this also changes our physical balance. A change in the physical balance affects the balance of the mind. They are all interdependent.
Therefore, we need to take care if we want to have a healthy body and a happy mind. We need to take care at all three levels: external factors, body, and mind.
In Tibetan Medicine, all diseases are traced to the bile, phlegm and wind in the body. Bile is the fire element , phlegm is the earth and water elements, and wind is the wind element. Most basically, all diseases—everything—is connected to these elements. Further, the bile, phlegm and wind types of diseases are connected with the three negative emotions. Bile is related to anger, phlegm is related to ignorance and wind is related to attachment.
This means that the principle of Tibetan Medicine is that, ultimately, all disease is ignorance. And the ultimate medicine is wisdom.