A stroke is caused by an interruption of blood flow to the brain, which leads to brain cell death. There are two main types of stroke with distinct causes:
- Ischemic stroke: This is the most common type, caused by a blockage in an artery supplying blood to the brain. The blockage can result from a blood clot or fatty deposits (plaque) that narrow or block the arteries. These clots may form due to atherosclerosis or irregular heartbeats like atrial fibrillation, which can cause clots to travel to the brain
- Hemorrhagic stroke: This occurs when a blood vessel in the brain bursts or leaks, causing bleeding in or around the brain. It can be triggered by high blood pressure, weakened blood vessels, trauma, or use of blood-thinning medications
There is also a transient ischemic attack (TIA), or "mini-stroke," where blood flow is temporarily disrupted but no permanent brain damage occurs. However, TIAs increase the risk of a full stroke
. Risk factors and causes that increase stroke likelihood include:
- High blood pressure (hypertension), the leading cause of stroke
- Diabetes, which damages blood vessels and raises stroke risk
- Heart conditions, especially atrial fibrillation and heart disease
- High cholesterol, contributing to artery plaque buildup
- Smoking and tobacco use, which raise blood pressure and promote clotting
- Obesity and lack of physical exercise
- Age, with risk doubling every decade after 55
- Family history and genetic predispositions
- Certain medications, excessive alcohol use, and illicit drugs like cocaine
- Other causes include artery spasms, cancer-related hypercoagulability, and cerebral venous thrombosis
In summary, strokes result from either blocked blood flow or bleeding in the brain, with high blood pressure and cardiovascular health being the most significant underlying causes
