[Research on the diseases Gu and Zhi in Huangdi Neijing].

Gu, a disease term which is described as 'gathering heat and pain on the lateral lower abdomen and passed some white worms' in Huangdi Neijing, was considered erosion of jingqi caused by bites of Gu (poisonous insects). This disease was named according to the way of seeking the cause from patterns identified, but it is not a kind of concrete parasitic disease. 'Zhi' in Huangdi Neijing does not mean protrusion. There was early knowledge about Zhi in Shiming, i.e. Zhi caused by bug bites. Zhi was probably named after chi (a kind of insect). Bleeding ulcers and sores in the anus reminded doctors in ancient times of the bites of insects. This disease was named Zhi because of chi's meaning of insects.