The causes of bleeding after hysteroscopy mainly include physiological phenomena, pathological conditions such as endometrial hyperplasia, endometrial polyps, endometrial cancer, etc. For different causes, the treatment methods are different. 1. Physiological phenomenon: Generally speaking, it is normal for women to have a small amount of vaginal bleeding after hysteroscopy. Because during hysteroscopy, it is necessary to dilate the uterine opening, which will inevitably cause damage to the endometrium, resulting in a small amount of endometrial detachment and thus a small amount of bleeding. 2. Endometrial hyperplasia: The endometrium and mesenchyme in the hyperplasia state have more elongated, expanded and curved spiral arteries supplying blood to the endometrium, which leads to the phenomenon of shedding of the hyperplasia after being stimulated by the instrument during the hysteroscopy, thus leading to bleeding after the hysteroscopy. 3. Endometrial polyp, endometrial cancer: endometrial diseases may have bleeding on the lesion wound after hysteroscopy. Therefore, after hysteroscopy, if there is bleeding symptom with small amount, there is no need to worry too much, in most cases, it is a normal physiological phenomenon, and you can take a rest and observe, if the bleeding increases or does not get better after observing, you should consult a doctor in time, so as to avoid delaying the condition.