What does it mean to enter the collaterals after a long illness? What are collaterals?

Long-term illness entering the meridians is a pathogenesis theory put forward by ancient physicians. Exogenous six evils or seven internal injuries invade the human body for a long time, but they are not cured. Evil spirits reach the meridians from the outside to the inside, from the fur to the viscera, and from the qi and blood, resulting in blood stasis between the meridians for a long time, but they do not heal. The clinical manifestations are stabbing pain in the affected area, immobility, dark tongue, unsmooth pulse and so on. Physicians use insects and ants to search the meridians to cure it.

Collaterals are the "collaterals" of meridians. The concept of meridians in traditional Chinese medicine can be divided into meridians and collaterals, as well as eight strange meridians. Meridians are divided into twelve meridians, which can be regarded as the main channels of meridians, and the branches separated from these main channels are collaterals. The concepts cannot be confused.