Granulomatous hemangioma, also known as septic granuloma, lobulated capillary hemangioma, purulent granuloma, capillary dilated granuloma, is a benign tumor that grows like a polyp on the skin or mucous membrane and is histologically characterized by the proliferation of capillaries to form lobular structures. There are several theories of its etiology as follows: 1. Trauma theory: About 1/3 of the cases have been confirmed that the mass is related to trauma. Infection theory: Infection is mainly caused by Staphylococcus aureus, but some people think it is caused by streptococcus. 3.Hormone expression theory: Patients with granulomatous hemangioma have increased estrogen expression, and estrogen receptors are expressed in some capillary hemangioma tissues. Mechanism of urea injection for hemangioma treatment: 1.After urea injection, the hemangioma tissues immediately show aseptic acute inflammatory changes, degeneration, infiltration and proliferation, and after 1~2 weeks, the inflammation subsides and the new connective tissue replaces the hemangioma tissues; 2.Urea can destroy the cell matrix; 3.Urea is a cytotoxic agent, which can inhibit the growth and proliferation of tumor cells and act directly on the tumor organelle enzyme system, such as alkaline phosphatase, lactate dehydrogenase Urea is a cytotoxic agent that can inhibit the growth and proliferation of tumor cells, and act directly on tumor cell organelle enzyme system, such as alkaline phosphatase, lactate dehydrogenase or nucleases related to polynucleotide peptide synthesis to affect polynucleotide metabolism; 4.High concentration of urea can open the protein chain and cause structural changes of amino acid side chain and protein peptide main chain, resulting in protein denaturation and dissolution; 5.The high osmotic pressure of urea used can kill tumor cells; 6.In addition to the effect on the cells themselves, urea may also act on the immune system of the body. Urea injection therapy for the treatment of granulomatous hemangioma has the characteristics of exact efficacy, no bleeding, no scar formation and pigmentation after treatment, and not easy to recur; and the method is simple, cheap and safe to use.