Tibetan Medical Science Depicted on Thangka
　　
　　Thangka is a kind of roll painting on colored silk, and as high artistic value. It is said that the oldest Thangka, depicting the White Lhamo, was made by King Songtsan ;Gambo using blood from his nose in the 7th century. However, it is no longer extant.

　　The colors used in Thangka will not fade because of ~e special pigments used, made of opaque minerals, plants, animal glue and bile of cattle.
The themes of Thangka cover a wide range of subjects, including religion, history and daily life. Some are related to the Tibetan calendar and astronomy, and Tibetan medical science.
　　
　　Thangkas were also used by Tibetan doctors as wall charts.
As early as in the 8th century, Yutog Yoindain Goinbo, the founder of traditional Tibetan medicine, compiled the Four Medical Classics. In the 15th century, the northern school of Tibetan medicine added annotations to the work to expound the measurements of the internal organs of human body in anatomy by means of medical Thangka charts. In the 17th century, Des Sangyai Gyaco finished his Blue Glaze Annotations of the Four Medical Classics. This work was printed and distributed all over Tibet in 1689. Later, he called noted painters in Tibet together to produce 79 colored Thangka charts depicting medicinal herbs.

　　Using the medical Thangka charts to show the causes and changes of illnesses, doctors could prescribe the right medicine. Four big trees represented the Tibetan medical tradition.

　　The charts instruct doctors how to prescribe the right medicine for an illness by asking questions, looking at the patient's face and tongue, and feeling the pulse before making a diagnosis.

　　Thangkas were also used as acupuncture points charts. Blood-letting methods are also described on Thangka charts.

　　In Tibetan medicine, herbs are considered of vital importance. Among the medical Thangkas that Des Sangyai Gyaco had made, six give details of 775 kinds of herbs. This figure is actually only a fraction of the total number of herbs used in Tibetan medicine.

　　Other Thangkas describe medical instruments and medicinal substances obtained from animals.