Hemangioma is a kind of benign tumor occurring in vascular tissue, which is formed due to the dislocation of vascular tissue and tumor like hyperplasia. The specific cause of this disease is not clear, but some studies have shown that it may be related to progesterone use during pregnancy, high-risk pregnancy, and low birth weight of the baby. In essence, hemangiomas can be divided into two types: one is vascular malformation (hamartoma) caused by abnormal vascular development, vascular overgrowth or abnormal differentiation during embryonic development. A true tumor caused by abnormal proliferation of vascular endothelial cells. The above health science knowledge is only for reference. If necessary, please go to the hospital for timely inspection and treatment.