What Causes Brain Stroke?

A brain stroke, also known as a cerebrovascular accident (CVA), occurs when there is a sudden disruption of blood flow to the brain, leading to the death of brain cells. This can happen due to two main types of strokes:

  1. Ischemic Stroke: Ischemic strokes are the most common type and occur when a blood vessel supplying the brain becomes blocked or narrowed, reducing blood flow to a specific area of the brain. The blockage is often caused by a blood clot, which can originate in the brain’s blood vessels (thrombotic stroke) or travel from other parts of the body, such as the heart or neck arteries (embolic stroke).
    • Thrombotic Stroke: This type of stroke occurs when a blood clot (thrombus) forms within one of the arteries supplying blood to the brain, often due to atherosclerosis, a condition where fatty deposits (plaque) build up on the arterial walls, narrowing the vessel and reducing blood flow.
    • Embolic Stroke: An embolic stroke happens when a blood clot or other debris (embolus) forms in another part of the body (e.g., the heart) and travels through the bloodstream to the brain, where it blocks a smaller blood vessel.
  2. Hemorrhagic Stroke: Hemorrhagic strokes are less common but often more severe. They occur when a blood vessel in the brain ruptures and causes bleeding into or around brain tissue. This bleeding can compress and damage brain cells.
    • Intracerebral Hemorrhage: This type of hemorrhagic stroke occurs when a blood vessel within the brain bursts and spills blood into the surrounding brain tissue.
    • Subarachnoid Hemorrhage: Subarachnoid hemorrhage happens when there is bleeding into the space between the brain and the thin tissues that cover it (subarachnoid space), often due to the rupture of a brain aneurysm—a weakened and ballooned blood vessel.

Causes and Risk Factors for Strokes include:

  • High Blood Pressure (Hypertension): Uncontrolled high blood pressure is the most significant risk factor for strokes, as it can damage blood vessel walls and promote clot formation.
  • Smoking: Smoking tobacco products can increase the risk of stroke by damaging blood vessels and promoting atherosclerosis.
  • Heart Disease: Conditions like atrial fibrillation (an irregular heart rhythm) and heart valve abnormalities can increase the risk of blood clots forming in the heart and traveling to the brain.
  • Diabetes: Uncontrolled diabetes can damage blood vessels and increase the risk of atherosclerosis.
  • High Cholesterol: Elevated levels of cholesterol can contribute to the formation of plaque in blood vessels.
  • Physical Inactivity: Lack of regular exercise can contribute to other stroke risk factors, such as high blood pressure, obesity, and diabetes.
  • Family History: Having a family history of strokes or certain genetic conditions can increase the risk.
  • Age and Gender: The risk of stroke increases with age, and men tend to have a slightly higher risk than women.
  • Race and Ethnicity: Some racial and ethnic groups, such as African Americans and Hispanics, have a higher risk of strokes.
  • Prior Stroke or Transient Ischemic Attack (TIA): Having a previous stroke or mini-stroke (TIA) increases the risk of subsequent strokes.

It’s essential to recognize the signs of a stroke and seek immediate medical attention if someone shows symptoms such as sudden weakness or numbness in the face, arm, or leg (especially on one side of the body), difficulty speaking, severe headache, and trouble with vision. Early intervention can significantly improve the outcome and reduce the potential for long-term disability resulting from a stroke.