A condition in which an organ or tissue receives an inadequate supply of blood, depriving it of oxygen and nutrients. In the context of nutrition and cardiovascular health, ischaemia of the heart muscle underlies angina and heart attacks, usually because narrowed coronary arteries cannot meet the heart’s oxygen demand. Risk factors include diets high in saturated fat and salt, smoking, hypertension, and diabetes. Transient ischaemia may cause pain or dysfunction that resolves when blood flow returns, while prolonged ischaemia leads to tissue death. Prevention centres on heart-healthy eating patterns, regular physical activity, blood pressure control, and cholesterol management.