I am simple Coronary heart disease (CHD) is one of the commonest diseases to affect the heart. It's usually caused by atherosclerosis, a build up of fatty materials within the walls of the arteries. Dr Jeni Worden last medically reviewed this article in January 2010. On this page * What is CHD? * Symptoms of CHD * Causes of CHD * Other heart diseases Page options * Print this page What is CHD? In CHD, the arteries that supply the heart with oxygen and nutrients become narrowed by atherosclerosis restricting the supply of blood and oxygen to the heart, particularly during exertion when there are more demands on the heart muscle. Top Symptoms of CHD The main symptom is angina, caused by insufficient oxygen reaching the heart muscle because of reduced blood flow. Angina is a feeling of heaviness, tightness or pain in the middle of your chest that may extend to your arms, neck, jaw, face, back or abdomen. The following symptoms are by no means always owing to CHD, and could be harmless or caused by other medical conditions. However, if you experience any of them it's a good idea to make an appointment to see your doctor: * Unusual breathlessness when doing light activity or at rest, or breathlessness that comes on suddenly * Palpitations - awareness of your heart beat or a feeling of having a rapid and unusually forceful heartbeat, especially if they last for several hours or recur over several days and/or cause chest pain, breathlessness or dizziness * Fainting - although not always a serious symptom, fainting is due to insufficient oxygen reaching the brain, so you should report it to your doctor * Fluid retention or puffiness (the medical term is oedema) is an abnormal accumulation of fluid in the tissues of the ankles, legs, lungs or abdomen, for example. Although a mild degree of ankle oedema may be quite normal - for example, on a hot day - it can be a sign that the heart isn’t pumping as well as it should (this is known as heart failure). Fluid retention in the lungs, or pulmonary oedema, can cause intense shortness of breath, and may be life-threatening * Bluish-tinged fingernails or lips (known medically as cyanosis) can be the result of too little oxygen in the blood * Fatigue is a common symptom of heart disease, but has numerous causes, including depression. It's always worth seeing your doctor if you feel unusually tired, especially if this is combined with symptoms that can’t be explained Top Causes of CHD The most common cause is atherosclerosis, a build up of fatty materials within the walls of the arteries throughout the body, most importantly in the arteries to the tissues of the heart - the coronary arteries. During this process, the inner lining of the arteries becomes furred with a thick, porridge-like sludge (atheroma), consisting of fatty deposits of cholesterol, cell waste and other substances. These form raised patches on the artery wall - known as 'plaques' - that narrow the arteries, reducing the space through which blood can flow. At the same time, the blood becomes more prone to clotting. These growing plaques may block the delivery of nutrients to the artery walls, causing the arteries throughout the circulation to lose their elasticity. In turn, this can lead to high blood pressure, which also increases the risk of CHD. A heart attack occurs when one of the coronary arteries blocks completely. This final step usually happens when a plaque splits open for some reason, causing a blood clot to form on its surface that obstructs the flow of blood. It’s not yet understood why plaques split open, but inflammation seems to play a part. When the supply of oxygen and nutrients is completely blocked, the heart muscle and tissue supplied by that artery dies. Some people are particularly predisposed towards developing atherosclerosis, due to inherited genetic factors. They may have a family history of people dying at a young age from CHD. An unhealthy diet, lack of exercise, diabetes, high blood pressure and smoking all increase the risk. Top Other heart diseases Other diseases that commonly affect the heart include: * Infection - bacterial infections are much rarer these days thanks to antibiotics, but can damage the valves of the heart as well as other tissues. Viral infections can damage the heart muscle leading to heart failure, or cause abnormal heart rhythms. * Congenital heart disease - there's a range of structural abnormalities that can develop in the heart as a baby grows in the womb. These may cause abnormal flow through the heart (for example, through a septal defect or hole in the heart) or through the rest of the circulation, and put excessive strain on the infant's heart after it's born. * Cardiomyopathy - this is disease of the heart muscle and may occur for many different reasons, including CHD, high blood pressure, viral infection, high alcohol intake and thyroid disease. For many people with heart disease, there is a combination of factors that can cause problems. For example, CHD (most adults have some degree of atherosclerosis, especially if they smoke) and high blood pressure are often found together.