It can partially or totally block the flow of blood through an artery to the brain. The brain cells then die from lack of oxygen. The products released when cells die cause swelling in the brain. Since the skull doesn't allow much room for expansion, this swelling can damage the brain tissue even further. Strokes can cause many different signs and symptoms, depending on the area of the brain that is damaged.
Some people have multiple areas of damage.
Most strokes begin suddenly, develop rapidly, and cause brain damage within minutes. These are often on only one side of the body. In some cases, people may only have weakness or clumsiness in their hand. This may require a person to be put on an artificial breathing machine, or ventilator . A stroke from atherosclerosis is caused by the buildup of plaque on the inner walls of arteries supplying the brain.