Benign fibroids are usually not cancerous, but not 100%. The probability of fibroids becoming malignant is 0.4%-0.8%, its malignant rate is very low, but it should be concerned. How to know its malignant change is as follows: 1) how big the fibroids are by ultrasound examination to have an idea; 2) conscious symptoms, i.e. typical bleeding; 3) pressure symptoms, the grown fibroids will form pressure on the bladder and rectum. Therefore, once you find that there are changes in the conscious symptoms, such as bleeding, frequent urination, urgent urination, bowel irregularities, and compression symptoms, even if it is a little bleeding, you should pay attention to it, so that you should consider whether there are any changes in the fibroids and any malignant changes. Therefore, although the incidence of benign uterine fibroids is very low, monitoring in place will reduce the occurrence.