An ischaemic stroke is caused by a blood clot. It can occur in two ways:
Embolic stroke – when a blood clot forms in the body, usually the heart, and travels through the bloodstream into the brain where it is lodged in a blood vessel. Thrombotic stroke – caused by deposits of cholesterol plaques, that adhere to the inner wall of an artery, usually in the neck, and block the flow of blood to the brain.