A stroke occurs when the blood supply to the brain is interrupted or reduced, cutting off oxygen and nutrients. The symptoms depend on which area of the brain is affected but may include paralysis, weakness, confusion, vision changes, and severe headaches. There are two main types of strokes: ischemic, caused by a blockage, and hemorrhagic, caused by a ruptured blood vessel. Risk factors include high blood pressure, cholesterol, smoking, diabetes, alcohol, age, and family history. Prevention focuses on controlling risks like blood pressure, cholesterol, weight, and diabetes through lifestyle changes like diet, exercise, and avoiding smoking. The first aid treatment is to maintain an open airway and minimize brain damage until urgent medical help arrives