The combination of leech and dillon can activate blood circulation and remove blood stasis (promoting blood circulation and eliminating blood stasis in the body). Leech is the dried whole body of leech of the genus Leech, family Hirudinea, with the effect of breaking blood circulation and promoting menstruation, eliminating blood stasis and eliminating symptoms, used for treating blood stasis and menstrual occlusion, obstruction in the abdomen, lumps, hemiplegia and injuries caused by falling and thrashing. Patients with bleeding tendency and pregnant women should not use this medicine. Dilong is the dried body of Gastrodactylosoma cervicornis, which has the effects of clearing away heat, calming convulsions, clearing collaterals, calming asthma, and inducing diuresis. It is used for high fever, convulsions, joint paralysis, numbness of limbs, hemiplegia (one side of the limbs can not move freely), coughing and wheezing with lung fever, edema and urination. Patients with weak spleen and stomach, pregnant women should not use this medicine. When used together, they can have the effect of activating blood circulation, removing blood stasis and clearing collaterals, and can be used to treat Qi stagnation and blood stasis (stagnation of blood due to lack of circulation of Qi) syndrome. Patients who need to use the drug should do so under the guidance of a doctor to avoid adverse consequences.