Final answer:
An ischemic stroke is caused by a blockage in a brain artery due to an embolus, like fatty tissue or blood clot, and represents the majority of stroke cases. Contrasting with hemorrhagic strokes, ischemic strokes result from interruptions in blood flow leading to brain cell death.
Step-by-step explanation:
The type of stroke that occurs when fatty tissue, which has accumulated over years, breaks free and becomes lodged in an artery in the brain is known as an ischemic stroke. This condition is often the result of an embolus—a blood clot or fat deposit—that obstructs the flow of blood. Ischemic strokes are caused by such blockages which can lead to a significant decrease in blood flow (ischemia), causing the death of brain cells due to a lack of oxygen. An embolus may originate from a build-up in the carotid artery or from a part of the heart, especially if there are conditions like arrhythmia.
Managing risk factors such as high blood pressure, diabetes, high cholesterol, and smoking is imperative to reduce the risk of an ischemic stroke. In contrast to ischemic strokes, hemorrhagic strokes occur when an artery ruptures in the brain, leading to bleeding and potential brain cell death due to physical pressure and loss of blood flow to areas beyond the site of hemorrhage.