The American Heart Association says that stroke is the number 3 killer disease in the United States, after heart disease and cancer. A stroke occurs when blood flow to the brain is reduced or blocked entirely. When this happens, the brain is deprived of oxygen and nutrients, which then leads to the death of brain cells and symptoms of stroke. The main causes of stroke include cerebral hemorrhage, cerebral embolism and cerebral thrombosis.
Cerebral Thrombosis
According to “Nursing Practice: Hospital and Home: The Adult,” cerebral thrombosis is the most common cause of stroke. A thrombus is a blood clot that forms within the arteries in the brain. Cerebral thrombosis is a situation where blood vessels that deliver blood to the brain slowly become narrow due to the accumulation of blood clots on their walls. When these blood vessels become completely blocked, a stroke occurs as blood supply to the brain is cut off.
Atherosclerosis is the major cause of cerebral thrombosis. It is a condition where plaque–a combination of fatty materials and other substances in the body–sticks to and occludes the arteries in the brain. Rupture of this plaque causes blood clot or thrombus formation at the site and further occlusion of the brain arteries. A stroke occurs when the blood vessels supplying the brain become completely or severely blocked by the thrombus or plaque.
Cerebral Embolism
“An Introduction to Human Disease: Pathology and Pathophysiology Correlations” says that a cerebral embolism occurs less often than a cerebral thrombosis. An embolus is a blood clot or other substance such as a piece of fat, plaque or air that is capable of blocking blood vessels. An embolus is formed in another part of the body and travels to the brain through the bloodstream. A cerebral embolus causes a stroke when an embolus blocks arteries that supply blood to the brain. A myocardial infarction, atrial fibrillation and cardiac catheterization may lead to a cerebral embolism.
Cerebral Hemorrhage
Cerebral hemorrhage or bleeding in the brain can lead to a stroke. A cerebral hemorrhage occurs when an artery in the brain bursts or ruptures. “An Introduction to Human Disease: Pathology and Pathophysiology Correlations” suggests that a cerebral hemorrhage can occur in individuals who suffer from high blood pressure, which is also known as hypertension. Blood exerts pressure on the walls of the blood vessels as it moves through them. In hypertension, more pressure is exerted on the blood vessel walls.
About this Author
Ngozi Oguejiofo has been writing on a freelance basis since 2009 and most of her writings are focused on health. She is currently a registered nurse. She is interested in teaching, and writes articles focused on student nurses for various online publications.
