The main cause of a stroke is a disruption of blood flow to the brain. This can occur in two ways, leading to two main types of strokes:
- Ischemic Stroke: This type of stroke is caused by a blockage or narrowing of a blood vessel supplying the brain. The blockage is usually due to a blood clot or plaque buildup in the arteries, which reduces or completely blocks blood flow to a specific part of the brain. Ischemic strokes are the most common type, accounting for about 85% of all strokes.
- Hemorrhagic Stroke: This type of stroke is caused by bleeding in or around the brain. It occurs when a weakened blood vessel ruptures and releases blood into the surrounding tissue. The two main causes of hemorrhagic strokes are:a. Intracerebral Hemorrhage: This occurs when a blood vessel within the brain ruptures and leaks blood into the brain tissue. High blood pressure and structural abnormalities of blood vessels (such as aneurysms or arteriovenous malformations) are common causes of intracerebral hemorrhage.b. Subarachnoid Hemorrhage: This type of hemorrhagic stroke happens when there is bleeding between the brain and the thin tissues covering the brain (subarachnoid space). Subarachnoid hemorrhages are often caused by the rupture of an aneurysm, which is a weakened area in the wall of a blood vessel.
It’s important to note that there can be other contributing factors and risk factors for stroke, such as high blood pressure, smoking, diabetes, obesity, high cholesterol, a sedentary lifestyle, excessive alcohol consumption, certain heart conditions, and genetic predisposition. These factors can increase the likelihood of a stroke occurring. Managing and addressing these risk factors can help reduce the risk of stroke.