(Cerebrovascular Accident; CVA; Cerebral Infarct)
DefinitionStroke is a brain injury caused by an interruption in blood flow. Brain tissue that does not get oxygen and nutrients from blood can die within minutes. The damage to the brain can cause a sudden loss in bodily functions. The types of function that are affected will depend on the part of the brain that is damaged.There are two blood flow problems that cause a stroke. Strokes may be ischemic or hemorrhagic.
- An ischemic stroke is caused by a blocked blood vessel. It is the most common cause of stroke.
- A hemorrhagic stroke is caused by a ruptured blood vessel.
|Hemorrhagic vs. Ischemic Stroke|
|Copyright © Nucleus Medical Media, Inc.|
CausesAn ischemic stroke occurs when something stops the flow of blood. It may be a buildup or swelling of the walls of the blood vessels and/or something in the blood that becomes stuck in the blood vessel. A blockage in a small blood vessel will affect a smaller area of the brain. A blockage in larger blood vessels can block the flow of blood to several smaller blood vessels, leading to more brain damage.The blockage may be the result of one or more of the following:
- Atherosclerosis —a build-up of fatty substances along the inner lining of the artery that gradually decrease the area the blood can flow through
- A blood clot that has traveled from other parts of the body such as the neck or heart
- Inflammation of the blood vessels
Risk FactorsCertain factors increase your risk of stroke but can not be changed, such as:
- Race—People of African American, Hispanic, or Asian/Pacific Islander descent are at increased risk.
- Age: Older than 55 years of age
- Family history of stroke
- High blood pressure
- High cholesterol levels —specifically high-LDL bad cholesterol
- Low bone mineral density, especially in women
- Obesity and metabolic syndrome
- High blood homocysteine level
- Diabetes mellitus or impaired glucose tolerance
- Atrial fibrillation
- Blood disorders such as sickle cell disease and polycythemia
- Vascular dementia
- Disease of heart valves, such as mitral stenosis
- Prior stroke or cardiovascular disease, such as heart attack
- Peripheral artery disease
- Transient ischemic attack (TIA) —a warning stroke with stroke-like symptoms that go away shortly after they appear
- Conditions that increase your risk of blood clots such as:
- Certain autoimmune diseases
- Migraine with aura
- Having a blood vessel abnormality
- Previous pre-eclampsia
- Use of birth control pills , especially if you are over 35 years old and smoke
- Long-term use of hormone replacement therapy
- Pregnancy—due to increased risk of blood clots
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