“Dead Blood” or Si Xue (死 血) is a complicating factor in the treatment of martial arts and sports injuries and trauma in general. The first difficulty we encounter is the Chinese language itself and the flexible employment of the term “dead blood.” Dead blood is one of three terms that are sometimes used interchangeably to describe some kind of blood stasis. A standard interpretation is that when there is some kind of impairment of the movement of blood through the channels and collaterals, but the blood is not fully stopped, the condition is termed Blood Stagnation or Xue Zhi (血 滞).