Blood stasis syndrome, or blood stagnation (Chinese: Xue Yu) is an important underlying pathology of many disease processes according to traditional Chinese medicine. Described in TCM theory as a slowing or pooling of the blood due to disruption of Heart Qi, it is often understood in biomedical terms in terms of hematological disorders such as hemorrhage, congestion, thrombosis, and local ischemia (microclots) and tissue changes.