The most common symptom of coronary artery disease is angina or "angina pectoris," also known simply as chest pain. Angina can be described as a discomfort, heaviness, pressure, aching, burning, fullness, squeezing, or painful feeling due to coronary heart disease. Often, it can be mistaken for indigestion.

Angina is usually felt in the chest, but may also be felt in the shoulders, arms, neck, throat, jaw, or back.

If you have this symptom, take notice. If you've never been diagnosed with heart disease, you should seek treatment immediately. If you've had angina before, use your angina medications as directed by your doctor and try to determine if this is your regular pattern of angina or if the symptoms are worse. (This is called unstable angina, see below.)

What Causes Angina?
Angina is caused when blood flow to an area of the heart is decreased. This impairs the delivery of oxygen and vital nutrients to the heart muscle cells. When this happens, the heart muscle must use alternative, less efficient forms of fuel so that it can perform its function of pumping blood to the body. The byproduct of using this less efficient fuel is a compound called lactic acid that builds up in the muscle and causes pain. Some medications used to treat angina work by inhibiting the use of this fuel source.

What Are the Types of Angina?
The types of angina are:

Stable angina. The pain is predictable and present only during exertion or extreme emotional distress, disappearing with rest.
Unstable angina. This may signal an impending heart attack. Unstable angina is angina pain that is different from your regular angina pain or pain that occurs while at rest. The angina may occur more frequently, more easily at rest, feel more severe, last longer, or come on with minimal activity. Although this type of angina can often be relieved with medication, it is unstable and may progress to a heart attack. Usually more intense medical treatment or a procedure is required.
Prinzmetal's angina. This is when angina occurs at rest, when sleeping, or when exposed to cold temperatures. In these cases, the symptoms are caused by decreased blood flow to the heart's muscle from a spasm of the coronary artery. The majority of people with this type of angina also have coronary artery disease. These spasms occur close to the blockage.

Can Angina Occur Without Coronary Disease?
Angina can occur in the absence of any coronary disease. Up to 30% of people with angina with a heart valve problem called aortic stenosis, which can cause decreased blood flow to the coronary arteries from the heart. People with severe anemia may have angina because their blood doesn't carry enough oxygen. People with thickened heart muscles need more oxygen and can have angina when they don't get enough.
How Is Angina Evaluated?
To evaluate your angina, your doctor will first ask you a series of questions to determine what your symptoms are and what brings them on. After examining you, your doctor will order one or more of a series of tests to determine the underlying cause of the angina and the extent of coronary artery disease, if present. These tests include:

Exercise stress test
Electrocardiogram (ECG or EKG)
Stress imaging tests, such as nuclear tests or stress echocardiography. These are specialized imaging tests that can accurately localize the part of the heart that has decreased blood flow.
Cardiac catheterization

How Is Angina Treated?
The angina treatment you receive depends on the severity of the underlying problem, namely the amount of damage to the heart. For most people with mild angina, a combination of drugs and lifestyle changes can control the symptoms. Lifestyle changes include: eating a heart-healthy diet, lowering cholesterol, getting regular exercise, quitting smoking, and controlling diabetes and high blood pressure.

Some drugs used to treat angina work by either increasing the amount of oxygen delivered to the heart muscle or reducing the heart's need for oxygen. These medicines include:

Calcium channel blockers
Others angina drugs work to prevent the formation of blood clots, which can further block blood flow to the heart muscle. These medicines include:

Antiplatelet medications
For people with more serious or worsening angina, your doctor may recommend treatment to open blocked arteries. These include:

Coronary artery bypass grafting (CABG) surgery
External counterpulsation (EECP)
What Should I Do if I Have Angina?
With any type of angina, stop what you are doing and rest.

If you have been prescribed a medication called nitroglycerin to treat your angina, take one tablet and let it dissolve under your tongue. If using the spray form, spray it under your tongue. Wait five minutes.

If you still have angina after five minutes, take another dose of nitroglycerin. Wait another five minutes and if angina is still present, take a third dose.

If you still have angina after resting and taking two doses of nitroglycerin or 15 minutes, call for emergency help (dial 911 in most areas) or have someone take you to the local emergency room.

If you think you are having a heart attack, do not delay. Call for emergency help right away. Do not drive yourself to the hospital. Consider taking an aspirin. Quick treatment of a heart attack is very important to lessen the amount of damage to your heart.

Why Shouldn't I Drive Myself or Have Someone Drive Me to the Hospital?
When the ambulance arrives, the emergency personnel can begin to give you heart-saving care right away. They can start an IV to give you important drugs and give you oxygen to help improve the flow of oxygen-rich blood to your heart. Should problems occur, they are there to provide life-saving help as well.
Something to Remember About Angina
If you have angina, carry nitroglycerin with you at all times; you never know when you will need it. Nitroglycerin must be kept in a dark container. Keep it away from heat or moisture. Check the expiration date on the container. Once the container of nitroglycerin tablets is opened, it must be replaced every three months. The spray form has a longer shelf life and should be replaced every 2 years