Angina pectoris is recurring chest pain or discomfort that happens when heart muscle does not receive enough blood and oxygen. Angina pectoris, or simply angina, is a symptom of coronary heart disease. Arteries that carry blood to the heart can become narrowed and blocked because of atherosclerosis or a blood clot. Angina occurs when the heart muscle (myocardium) doesn’t receive an adequate amount of blood and oxygen needed for a given level of work. The chest pain associated with angina usually begins with physical exertion. Other triggers include emotional stress, extreme cold and heat, heavy meals, excessive alcohol consumption, and cigarette smoking. Angina chest pain is usually relieved within a few minutes by resting or by taking prescribed cardiac medications, such as nitroglycerin. An episode of angina doesn’t mean that a heart attack is occurring or is about to occur. Angina does indicate, however, that coronary heart disease is present and that some part of the heart isn’t receiving adequate blood flow. People with angina have an increased risk of heart attack. A person who has angina should note the patterns of his or her symptoms: what causes the chest pain, what it feels like, how long episodes usually last, and whether medication relieves the pain. Call for medical assistance if the symptoms of an angina episode change sharply. In addition to a complete medical history and medical exam, a physician can often diagnose angina by noting the patient’s symptoms and how/when they occur. Certain diagnostic procedures may also determine the severity of the coronary heart disease: Electrocardiogram (ECG or EKG): This test records the electrical activity of the heart, shows abnormal rhythms (arrhythmias or dysrhythmias), and detects heart muscle damage. Blood labwork: Troponin and creatine kinase concentrations in the serum are very sensitive biomarkers of myocardial injury. Stress test (usually with ECG; also called treadmill or exercise ECG): A test that’s given while a patient walks on a treadmill or pedals a stationary bicycle to monitor the heart during exercise. Breathing and blood pressure rates are also monitored. Cardiac catheterization: With this procedure, X-rays are taken after a contrast agent is injected into an artery to locate the narrowing, occlusions, and other abnormalities of specific arteries. The underlying coronary artery disease that causes angina should be treated by controlling existing risk factors: high blood pressure, cigarette smoking, high blood cholesterol levels, lack of exercise, excess weight, and a diet high in saturated fat. Medications may be prescribed to treat angina. The most common is nitroglycerin, which helps relieve pain by widening the blood vessels. This allows more blood flow to the heart muscle and decreases the heart’s workload. Note that there are two additional forms of angina pectoris: variant angina pectoris and microvascular angina. Variant angina is rare and occurs almost exclusively when a person is at rest. Attacks can be very painful and usually occur between midnight and 8 a.m. This type of angina is related to spasm of the artery. In microvascular angina, people experience chest pain but have no apparent coronary artery blockages. The pain results from poor functioning of tiny blood vessels that nourish the heart as well as the arms and legs.