Normal menstruation is dark red or bright red, without black blood clots. The reasons for a lot of black blood clots during menstruation are as follows: 1. Black blood clots during menstruation are related to blood stagnation and blood stasis, as well as poor menstruation, abdominal pain, chest pain, excessive menstrual volume and low menstrual volume, and can be regulated by drugs that promote blood circulation and eliminate blood stasis, such as motherwort. 2. Black blood clots during menstruation are related to blood and qi deficiency, as well as prolonged menstruation, abdominal pain, dizziness and pallor, and can be taken as blood tonics, oral liquids that replenish blood and strengthen nutrition and eat foods that replenish blood. 3, 3.Black blood clots in menstruation are related to blood cold, accompanied by delayed menstruation, low menstrual flow, abdominal pain, fear of cold, white tongue coating, you should pay attention to warmth, eat less cold food and drink more warm water. 4.Black blood clots in menstruation are related to kidney deficiency, accompanied by low menstrual flow, weakness of the waist and knees, dizziness and tinnitus, cold abdomen, nocturnal urination. Symptoms, you can eat black fungus, yam, chestnuts, wolfberry, he shou wu, etc. with the effect of kidney.