Strokes are primarily caused by either a blockage or a bleeding event that disrupts blood flow to the brain. These events fall into two main categories:
- Ischemic Stroke: This is the most common type, caused by a blood clot blocking an artery supplying blood to the brain. The clot may form from fatty deposits (atherosclerosis) or from blood clots traveling from the heart, often linked to conditions like atrial fibrillation or narrowed arteries.
- Hemorrhagic Stroke: This occurs when a blood vessel in the brain bursts or leaks, often due to high blood pressure weakening the arteries. Other causes include aneurysms, vascular malformations, amyloid angiopathy, trauma, or drug use.
Additional causes and risk factors include high blood pressure (the most significant risk factor), diabetes, smoking, obesity, heart disease, certain medications, age, family history, and race/ethnicity. Some genetic disorders, anemia, cancer, and even air pollution can also contribute to stroke risk.
Transient ischemic attacks (TIAs), or "mini strokes," result from temporary blood flow disruption and increase the risk of a full stroke.
In summary, strokes are caused by interrupted blood flow due to clots or hemorrhage, with many modifiable and non-modifiable risk factors influencing their occurrence.
