An ischemic stroke occurs when the blood supply to part of the brain is blocked or significantly reduced. This deprivation prevents brain tissue from getting oxygen and vital nutrients, causing brain cells to begin dying within minutes. It is the most common type of stroke, accounting for roughly 87% of all cases globally.
How It Happens
The blockage responsible for an ischemic stroke typically develops in one of two ways:
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Thrombotic Stroke: A blood clot forms directly inside an artery that supplies blood to the brain. This is frequently caused by atherosclerosis, a condition where fatty deposits (plaque) build up in the arteries and restrict blood flow.
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Embolic Stroke: A blood clot or piece of debris forms elsewhere in the body—very often in the heart or upper chest neck arteries—and travels through the bloodstream until it lodges in a narrower brain artery.
Common Signs and Symptoms
Medical professionals use the acronym B.E. F.A.S.T. to help people identify the sudden signs of a stroke:
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B – Balance: Sudden loss of balance or coordination.
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E – Eyes: Sudden trouble seeing or blurred vision in one or both eyes.
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F – Face Drooping: One side of the face droops or is numb when smiling.
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A – Arm Weakness: One arm feels weak or numb; when raising both arms, one drifts downward.
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S – Speech Difficulty: Slurred speech or difficulty repeating a simple sentence.
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T – Time to call emergency services: Every minute counts.
Risk Factors and Prevention
While some risk factors cannot be changed—such as age, family history, and genetic predisposition—many primary causes are highly manageable through lifestyle adjustments and medical care:
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High Blood Pressure (Hypertension): The leading manageable cause of stroke.
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Cardiovascular Disease: Conditions like atrial fibrillation (an irregular heart rhythm) significantly increase the risk of embolic clots.
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Lifestyle Choices: Smoking, a sedentary lifestyle, high cholesterol, and poorly managed diabetes accelerate plaque buildup in blood vessels.
An ischemic stroke is a profound medical emergency. Immediate treatment, such as clot-busting medications (tissue plasminogen activator) or mechanical procedures to physically remove the blockage, must be administered as quickly as possible to minimize permanent brain damage.