Shennong Bencaojing (Classic of Herbal Medicine)
One of the most important medical books to come out of the Han Dynasty was the Shennong Bencaojing (Classic of Herbal Medicine). The word bencao means essential herb. While its attributed author is the Fire Emperor discussed earlier, no one knows for sure who wrote it. What is known is that it was written between the 1st and 2nd century B.C., and is considered to be the earliest complete Chinese pharmacopoeia reference.

This book lists a total of 365 Chinese medicines from which 252 were of plant origin, 67 from animals, and 46 from minerals. Each medicine was divided into one of three categories. The superior category included 120 medicines, which were considered to be non-toxic and contain invigorating effects to preserve vitality or prolong life. One of the most famous herbs in this category is ginseng (Panax ginseng). The second category included average medicines of which 120 were listed. Medicines in this category were used to prevent illness and restore the individual's vitality. However, the medicines listed here containing herbs such as Chinese angelica (Angelica sinensis) and ephedra (mahuang) could sometimes be toxic and should be used carefully for certain ailments. The third category included 125 inferior medicines that were considered to be toxic with side effects, and were specifically used for therapeutic purposes to treat diseases. Croton (Croton tiglium) is an example of an herb in this category which helps to relax the bowels, relieve edema (swelling) or eliminate phlegm evils.

Ginseng             
Superior category

Chinese angelica                                                                                       Ephedra

The second category

Croton tiglium
The third category

Prominent Physicians of the Han Dynasty
During the Han Dynasty several prominent physicians emerged. Chunyu Yi (215167 B.C.) was the first doctor to keep medical records on the patients he treated. Guo Yu, who was the court physician of Emperor He, and Fu Weng were two doctors of the first century A.D. who were renowned for their skills in acupuncture and moxibustion.

A copy from Shanghan zabzabinglun (Discourse on Fevers and Miscellaneous Illnesses)

Zhang Zhongjing also known as Zhang Ji (150219 A.D.) was considered to be a 'sage of medicine.' He penned a book called Shanghan Zabzabinglun (Discourse on Fevers and Miscellaneous Illnesses), which dealt with the treatment of many febrile conditions. The book contains six parts, which correspond to the six pairs of meridians. It is significant because it discusses diagnosis and treatment methods based on an assessment of the symptoms of different pathological conditions. Later in the Song dynasty (9601279A.D.), his book was rewritten and divided into two books called Shanghanlun (Treatise on Febrile Diseases) and Jinkui yaolue (Summary from the Golden Chest).

Hua Tuo (141208 A.D.) was a contemporary of Zhang Zhongjing. He traveled from town to town treating patients and learning from other doctor's practices. He is famous for his skill as a surgeon and his use of anesthesia. The anesthesia was given as a powder called mafeisan that was dissolved in a fermented drink before performing surgery. It has been suggested the powder may have been hemp since its uses were unknown at that time. Besides performing surgeries, Hua Tuo also recommended the use of physical exercises for his patients. He devised movements that were similar to the movements of five different animals. These were the tiger, deer, bear, monkey and bird. It is said that one of his disciples Wu Pu lived to be 90-years-ol＆d due to these exercises. Another of Hua Tuo's disciples called Fan A was a great acupuncturist. He devised methods to extend it use to the back and thorax. Unfortunately many of Hua Tuo's works have been lost, and surgery became unpopular because most Chinese beliefs and laws of the time did not look favorably on it.

Dong Feng was another well-known physician who practiced towards the end of the Han Dynasty during the reign of Emperor Xian.

The end of the Han Dynasty
In 184 A.D., the Yellow Turbans successfully broke up the Han Dynasty. The army generals held the real power and this led to the Three Kingdoms period of the 3rd century A.D. One general called Cao Cao was especially militant. He has requested Hua Tuo to remain in his service after being treated for a migraine headache. After Hua Tuo refused, Cao Cao had him killed.

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