A: Yuthog Yuntangoinbo, author of the Four Medical Classics, is founder of the Tibetan medicine. According to Tibetan medicine, the human body's physiological functions are generated by three primary elements: long, chiba and peigen. Long sustains life, circulates breath and blood, moves limbs, and decomposes food; chiba, namely bile, generates and regulates the body temperature, gives the face a healthy color, breeds wisdom and assists digestion. Peigen, namely saliva, supplies nutrition, develops fat, regulates skin, and ensures good sleep. Tibetan doctors believe a balance of the three elements can regulate the normal physiological functions of the human body, and that any imbalance leads to ailments.
Tibetan doctors also believe that the human body is composed of 7 substances: essence of food, blood, flesh, fat, bone, marrow and fluid. People's five solid viscera (heart, liver, spleen, lung and kidney) and six hollow organs (gallbladder, stomach, small intestine, large intestine, bladder and sanjiao) are connected with one another through channels and collaterals. The human body is closely linked to nature, and all physiological functions are affected by changes in nature.
The main diagnostic methods of Tibetan medicine are observation, palpation and interrogation. Doctors also pay close attention to the patients' urine during examination. Treatment includes not only medicines made of plants, animals and minerals, but also therapies such as acupuncture and bloodletting.
Embryology is an important component of Tibetan medicine. Tibetan doctors started research on embryology in the 7th century. The Four Medical Classics has detailed records of the whole process of embryo development. There is also an account in the Five Volumes of Biography which states: "The embryo goes through three stages-first fish, then tortoise, then pig." Tibetan doctors started research on diverse fields of human physiological development far earlier than their foreign counterparts.