Blood stasis:
This is a pathological state in which circulation of blood is obstructed and stagnated or blood escapes from the vessel and accumulates subcutaneously or in internal organs. Blood is substantial. If the escaped blood stays among muscles, it will lead to swelling; if it stays subcutaneously, it will result in ecchymoses. Stagnated blood gives rise to pain. So there is local pain, which is of stabbing nature and fixed in focus. There is also dark complexion, dry and squamous skin, dry hair, cyanosis of lips, purple tongue, thready or uneven pulse.

Blood deficiency:
It is a pathological condition in which the blood fails to nourish skin, muscle, tendon, bone, meridians and viscera due to shortage of blood in the body. It is often caused by massive bleeding; or dyshematopoiesis with asthenia of the heart and spleen due to consumption of healthy qi in either general weakness or a long period of trauma; or deficiency of liver-blood and kidney-essence due to serious trauma of tendon and bone involving the liver and kidney; or no production of fresh blood because of existence of stagnant blood. The main manifestations are dizziness, vertigo, pale or sallow complexion, palpitation, insomnia, amnesia, tendon flaccidity, numbness of limbs, impaired movement of joints, pale nail, pale tongue, thready pulse, etc.

Blood heat:
This means that there is heat in the blood. It is often caused by production of heat from stasis after trauma, or infection of pathogen-poison from incised wound. The main manifestations are fever, bitter taste in the mouth, thirst, restlessness, red tongue with yellow coating and rapid pulse. In the severe cases, there may be high fever and coma or mania; if pathogen-poison infection produces heat because of stagnation, it may cause putrefaction of muscle leading to purulent sore. If blood is forced by heat and the vessel is obstructed, there may occur bleeding of various types, such as epistaxis, hematemesis, hemoptysis, hemafecia, hematuria and hematohidrosis.