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 a cerebrovascular malformation? Under normal circumstances, the human brain is like a busy city, and the blood vessels in the brain are the city’s transportation network, with straight main roads and winding paths. The blood vessels in the brain are like a network of roads, with arteries and veins intertwined and connected. Blood normally flows in from the arteries, passes through the capillary beds and reaches the veins before exiting. However, in special cases, such as congenital developmental abnormalities, the arteries and veins are directly connected, resulting in the formation of abnormal localized blood vessel clusters. The blood vessels within the vascular clusters 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 a simple guardrail erected on both sides, resulting in blood only flowing along the blood vessels, but not from the “fork” outflow, but directly through the blood vessel cluster outflow, which makes the brain tissue where the blood vessel cluster is located can not get the normal blood supply, resulting in dysfunction, i.e., cerebral vascular malformation. Doctor’s tip: Some vascular malformations may rupture and bleed, and serious bleeding can be life-threatening. Therefore, after discovering vascular malformations, no matter whether they are ruptured or not, they should be treated actively.