Background
In TCM, xuè yū (blood stasis) is broader than a blood clot in the Western sense. It describes any state where blood is not flowing freely — a fixed, stabbing pain (as opposed to a moving, aching one), dark or purplish discoloration, lumps or masses, and in women's health, menstrual clots or a delayed, painful period. The "stuckness" can arise from trauma, from cold congealing the blood, from qi failing to move it, or from long-standing deficiency that leaves the vessels empty and sluggish. Guizhi Fuling Wan addresses blood stasis in the lower abdomen — its classic application is masses or pain in the uterus area. Dieda Wan addresses traumatic blood stasis — the kind that follows a fall, impact, or sports injury. Both share the same "stuck blood" logic, but one arises from internal accumulation and the other from external force.