What Causes a Stroke?

A stroke occurs when the blood supply to a part of the brain is disrupted, leading to damage or death of brain cells. The two main types of stroke are ischemic stroke and hemorrhagic stroke, and they have different causes:

  1. Ischemic stroke: This type of stroke occurs when a blood vessel supplying the brain becomes blocked or narrowed, reducing blood flow. The most common cause of ischemic stroke is the formation of a blood clot within a blood vessel in the brain. The clot can develop locally in a narrowed artery due to atherosclerosis (buildup of fatty deposits), or it can originate from a different part of the body (such as the heart) and travel to the brain (embolic stroke). Risk factors for ischemic stroke include high blood pressure, smoking, diabetes, high cholesterol, obesity, and a sedentary lifestyle.
  2. Hemorrhagic stroke: This type of stroke occurs when a blood vessel in the brain ruptures, leading to bleeding in or around the brain. The most common cause of hemorrhagic stroke is hypertension (high blood pressure), which weakens blood vessel walls over time, making them more prone to rupture. Other causes include the rupture of an aneurysm (a weak, bulging area in a blood vessel) or arteriovenous malformation (an abnormal tangle of blood vessels).

Other factors that can increase the risk of stroke include:

  • Age: The risk of stroke increases with age, particularly over the age of 55.
  • Family history: Having a family history of stroke or certain genetic conditions can increase the risk.
  • Gender: Men have a slightly higher risk of stroke than premenopausal women, although the risk evens out after menopause.
  • Race and ethnicity: Some ethnic groups, such as African Americans, have a higher risk of stroke.
  • Prior stroke or transient ischemic attack (TIA): Having a previous stroke or TIA increases the risk of subsequent strokes.
  • Certain medical conditions: Conditions such as atrial fibrillation (an irregular heart rhythm), heart disease, carotid artery disease, and certain blood disorders can increase the risk of stroke.
  • Lifestyle factors: Unhealthy lifestyle choices such as smoking, excessive alcohol consumption, poor diet, physical inactivity, and drug abuse can contribute to the risk of stroke.

It’s important to note that identifying and managing stroke risk factors, adopting a healthy lifestyle, and seeking prompt medical attention for any concerning symptoms can help reduce the risk of stroke.