The main difference between residue and bruise is that if it is bruise, it will be flowing and liquid dark area; if it is residue, a mixed echogenic mass will be found in the uterine cavity through ultrasound examination. It is recommended to give a comprehensive analysis with the clinical history. If there is a liquid dark area in the uterine cavity, it indicates that there has been a history of abortion or induction of labor, and oral Wujia Biochemical Capsules can be taken to promote the discharge of bruised blood for treatment purpose. If there is an inhomogeneous mixed echogenic mass in the uterus through ultrasound examination, the uterus can be cleared clinically and the cleared tissues can be examined by laboratory for final pathological diagnosis.