Blood stasis may be caused by qi deficiency, qi stagnation, cold congealment and trauma. 1. Blood stasis due to qi deficiency: This refers to the weakness of qi that leads to the inability to transport blood, resulting in stagnation of blood flow. It is often caused by the internal stagnation of silt and blood due to prolonged Qi deficiency, which may result in pale face, tiredness and fatigue, accompanied by shortness of breath, shortness of breath and other symptoms. 2. Qi stagnation and blood stasis (blood stagnation due to poor circulation of qi): mostly caused by emotional discomfort (emotional discomfort), or external evil attack causing liver qi stagnation (poor circulation of qi and blood in the liver and depression) leading to poor circulation of blood and blood stasis, which is mainly manifested as chest and rib swelling and tightness, impatience and irritability, and female patients may also experience dysmenorrhea, dark menstruation and blood clots. 3. Cold condensation and blood stasis: Due to the invasion of cold evils, the blood is cold and congealed due to cold condensation. Patients may have cold limbs, cold pain in the abdomen, small amount of menstrual blood, or even amenorrhea, infertility, and so on. 4. Trauma: Trauma leads to damage of local blood channels, blood overflows outside the veins, unable to run, forming localized blood stasis, accompanied by localized pain and refusal to be pressed, fixed and immovable. Patients with blood stasis syndrome should consult a professional Chinese medicine practitioner for diagnosis and treatment and guidance on the use of medication in order to improve the disease.