Strokes are caused by problems with blood flow to the brain, either through blockage or rupture of a blood vessel. The specific causes vary depending on the type of stroke:

1. Ischemic Stroke

Ischemic strokes, which account for about 87% of all strokes, occur when a blood clot obstructs a blood vessel that supplies blood to the brain. The clot stops blood flow, depriving brain tissue of oxygen and nutrients. This type of stroke can happen in two ways:

  • Thrombotic Stroke: This occurs when a blood clot (thrombus) forms in one of the arteries supplying blood to the brain. It often develops around atherosclerotic plaques.
  • Embolic Stroke: This occurs when a blood clot or other debris forms away from the brain — commonly in the heart — and is swept through the bloodstream to lodge in narrower brain arteries. This type is often associated with heart problems, including atrial fibrillation.

2. Hemorrhagic Stroke

Hemorrhagic strokes happen when a blood vessel in the brain bursts, leading to bleeding (hemorrhage) either directly into the brain (intracerebral hemorrhage) or between the brain and the skull (subarachnoid hemorrhage). Common causes include:

  • Uncontrolled High Blood Pressure (Hypertension): The most common cause of hemorrhagic stroke, which can weaken the blood vessel wall over time.
  • Aneurysms: Weak spots in blood vessel walls that bulge and can burst.
  • Arteriovenous Malformations (AVMs): Abnormal tangles of blood vessels in the brain that can rupture.
  • Trauma: Such as a head injury that leads to cerebral hemorrhages.
  • Blood-thinning Medications: Overuse or improper use of anticoagulants can increase the risk of hemorrhage.

3. Transient Ischemic Attack (TIA)

A TIA, or mini-stroke, is caused by a temporary clot or blockage in an artery leading to the brain. The causes are similar to those of ischemic strokes, but the blockage is brief and doesn’t cause permanent damage. Nonetheless, TIAs should be treated urgently as they often precede full-blown strokes.

Common Risk Factors Contributing to Strokes:

  • Age: Older individuals are at higher risk.
  • Family History: A family history of stroke increases your risk.
  • High Blood Pressure: The leading risk factor for strokes.
  • Smoking: Significantly increases stroke risk due to circulation problems it causes.
  • Heart Disease: Conditions like atrial fibrillation, heart valve disease, and others increase the risk of clots.
  • Diabetes: Increases the risk of atherosclerosis and stroke.
  • Cholesterol Levels: High levels of LDL cholesterol can lead to plaque formation and subsequent strokes.
  • Obesity: Associated with high blood pressure, diabetes, and heart disease.
  • Physical Inactivity: Can worsen other risk factors for stroke.
  • Heavy or Binge Drinking: Can lead to high blood pressure and an increased risk of hemorrhagic stroke.
  • Drug Use: Drugs such as cocaine and methamphetamines can increase stroke risk.

Understanding these causes and managing risk factors through lifestyle changes and medical treatments can significantly reduce the risk of having a stroke. Regular medical checkups and screenings are vital, especially for those with risk factors.

Categorized in:

Cardiovascular, Strokes,

Last Update: May 28, 2024