Menstrual blood clots are dissolved when placed in water, and the endometrial lining floats when placed in water, so the naked eye can tell whether it is a blood clot or the endometrial lining that has been shed. Menstruation consists of the shed endometrium, cervical secretion mixed with blood, which is discharged through the vagina. The blood clots and endometrium are dark red in color, and the endometrium is a fleshy tissue with grayish-white mucous membrane tissue attached to it. Normally, the endometrium is shed in fragments during a woman’s menstrual period, with occasional large clots, without symptoms such as abdominal pain. It is also normal for menstruation to occur without advancement or delay. Frequent shedding of large pieces of endometrium during menstruation may be caused by endocrine disorders, endometrial thickening, or ovarian tumors, which need to be examined and treated in the hospital. Usually moderate exercise to enhance physical fitness, try to avoid eating spicy cold food, menstruation, if discomfort, it is recommended to timely go to the hospital, follow the doctor’s instructions to deal with treatment.