A malformation is an abnormality in the genetic system of a patient’s body that causes a part of the organism to develop abnormally, resulting in a shape that is different from the normal shape. So what is cerebrovascular malformation? Under normal circumstances, the human brain is like a busy city, and the blood vessels in the brain are the traffic road network in the city, with straight main roads and winding paths. The blood vessels in the brain are like a network of roads, with arteries and veins interconnected. Blood generally flows in from the arteries and out through the capillary beds to the veins. However, in special cases, such as congenital developmental anomalies, the arteries and veins are directly connected and an abnormal vascular mass is formed locally. The vessels within the vascular mass often do not have a normal vessel wall structure, but are formed by fibrous tissue. These blood vessels are like a road under construction, with simple guardrails on both sides, so that blood can only flow along the blood vessels, and cannot flow out from the “fork”, but directly through the vascular mass, thus making the brain tissue where the vascular mass is located unable to get normal blood supply, resulting in dysfunction, that is, cerebrovascular malformation. Warm tip: Some vascular malformations can rupture and bleed, and serious bleeding can be life-threatening, so when a vascular malformation is found, whether it ruptures or not, it should be treated actively.