Prescriptions for regulating blood circulation are chiefly composed of drugs that activate blood circulation. They bear the function of promoting blood circulation or arresting bleeding and are indicated for syndromes of blood stasis and hemorrhage.
  
Blood circulates incessantly in the vessels, but once the flow of blood is impeded, stagnation will be turned into stasis, blood will overflow from the vessels (namely bleeding syndrome). Therefore, this group of prescriptions is accordingly subdivided into prescriptions for activating blood flow to remove blood stasis and those for arresting bleeding.
   
The former mainly consists of drugs to activate blood flow and remove blood stasis and is indicated for blood accumulation and blood stasis syndrome due to stagnant blood in viscera or meridians and collaterals. The latter, however, is chiefly composed of drugs with styptic action and fit for hemorrhage at various locations of diseases as the result of extravasation of blood.
 
The former mostly possesses drastic and purgative effect and is apt to consume blood and impair healthy qi and liable to cause blood and fetus disorder.. Therefore drugs for removing blood stasis should not be used with an overdose, or it is advisable to use simultaneously drugs for building up body resistance to remove stagnant: blood without impairing healthy qi. Besides, it should be used with great caution in women with profuse menstruation or at pregnancy. The latter usually has an astringent action and is liable to cause blood stagnation, so they should be combined with some drugs that activate blood flow and remove blood stasis to prevent stagnation of blood.

In addition, whichever syndrome it is, it is certainly caused by cold and heat syndromes as well as excess and deficiency syndromes. Thus clinically, it is necessary to differentiate syndromes for etiology, distinguish between the primary and secondary aspects of the disease and determine severity of the disease. On this basis, therapeutic principle should be determined whether to treat the secondary or primary aspect, or deal with both simultaneously.