Chest pain may indicate presence of coronary artery disease. Coronary artery disease refers to build up of cholesterol deposits within the walls of the heart arteries, resulting in narrowing of the arteries and insufficient blood flow to the heart muscle. Coronary artery disease usually presents with chest pain or discomfort in the center or left side of the chest which may spread to involve the arms, jaw, neck or back. Other associated symptoms include breathlessness, sweating and nausea. The chest discomfort is usually first noticed during physical exertion (climbing stairs, walking). As the disease progresses, the chest discomfort occurs with less and less exertion and in severe cases as in the case of a heart attack, it may even occur at rest. Heart attack is the second leading cause of death in Singapore, after cancer.