Uterine fibroids 10mm*13mm are generally not serious if they are asymptomatic, but if they are symptomatic or affect pregnancy, they are more serious and need to be treated. Uterine fibroid 10mm*13mm belongs to relatively small uterine fibroids, most of them have no obvious symptoms, this situation is not serious, do not need special treatment, but the presence of the following conditions may be more serious. 1. In a small number of cases, although fibroids are relatively small, they can cause abnormal menstruation. It is more common to see submucous fibroids, which will increase the area of endometrium and affect the contraction of uterus, resulting in increased menstrual flow and prolonged menstrual period, which is a more serious situation. 2. There are some fibroids which are relatively small but affect the fertilized egg implantation and cause infertility, which are also more serious and need timely treatment. 3. If the fibroid grows rapidly, the suspicion of malignant transformation is also more serious. To sum up, whether the fibroid is serious or not does not depend entirely on the specific size, it should be decided according to whether there are symptoms, whether it affects pregnancy and whether it is malignant, etc. For the more serious cases, it is recommended to receive treatment actively.