Why blood vessels will break, because there is a complete set of hemostatic system in the human body, this hemostatic system consists of blood vessels themselves, platelets and coagulation factors are composed of three parts, no matter which part of the problem, may lead to blood vessel breakage bleeding. In addition to trauma (e.g., bleeding caused by sports or impact is the most common), the causes of blood vessel rupture are as follows: 1. Platelet abnormality: Whether it is a decrease in the number of platelets or the quality of the quality of the deterioration of the blood platelets, these will lead to blood vessel rupture and bleeding, such as idiopathic platelet purpura and regenerative anaemia. 2. Abnormalities in the function of the blood vessel wall: due to genetic factors, serious infections or Increased brittleness of capillaries can lead to blood vessel breakage. Similarly, atherosclerosis will make blood vessels harden, thicken and become brittle, lose elasticity and easily rupture when slightly injured.3. Abnormalities of coagulation factors: for example, congenital hemophilia will also cause blood vessels to rupture and bleed profusely. At the same time, the lack of nutrients in the blood, such as vitamin C and vitamin K deficiency, can cause blood vessel rupture. Vitamin K deficiency mainly causes the dysfunction of coagulation factors, which makes it difficult to stop bleeding after rupture of blood vessels, forming the phenomenon of blood vessel rupture and bleeding.