Blood nevus is more and more often considered to be caused by hemangioma, and patients may also be accompanied by symptoms such as elevated skin temperature and pain. Hemangioma is a kind of common vascular tumor lesion, which is mainly caused by the imbalance of balance between angiogenic factor and angiogenic inhibitory factor, extracellular matrix and protease expression changes, causing local microenvironmental changes and endothelial cell abnormality, leading to abnormal proliferation of vascular endothelial cells. Blood nevus is getting more and more firstly considered to be caused by hemangioma, and now the research thinks that it is related to skin aging. Patients will experience changes in skin color and morphology, and the appearance of red plaques with unclear boundaries. Some patients may be accompanied by varicose veins on the surface of the skin, elevated skin temperature, and may have purpura, petechiae, and in severe cases, symptoms of pain. If the patient appears to have more and more bloody nevi with age, he needs to go to the hospital in time to clarify the cause of the disease and take relevant treatment measures under the guidance of the doctor.