What causes a heart attack?

Most heart attacks happen when a blood vessel supplying part of the heart becomes blocked. When that part of the heart stops getting enough blood and oxygen, it can be damaged, causing a heart attack. Usually, the blockage is caused by a fatty material (plaque) that builds up on the inside of blood vessels and a blood clot.

Signs and symptoms of a heart attack vary from person to person. Many people feel severe chest pain, but some people have little pain or other symptoms instead. Here are some common heart attack symptoms:

* Chest pain. You may feel pain, pressure, or squeezing along the breast bone or in other parts of your chest. The pain or discomfort may spread to your arm, jaw, neck, or back. The pain might feel sharp, dull, or achy, and it doesn't go away when you rest or take medicine.

* Shortness of breath. You may have trouble catching your breath.

* Sweating and paleness. Your skin may become pale or look blue, and your arms and legs may feel cool and moist.

* Weakness, nausea, or stomach upset. You may vomit or feel queasy.

How will my healthcare provider know I'm having a heart attack?

If you think you may be having a heart attack, immediately call 911 for help instead of having someone drive you to the hospital. The healthcare provider or emergency responder will ask about your pain or other symptoms you're having, including when these symptoms started and if anything makes them feel better or worse. You'll be asked about medicines you're taking (prescription, over-the-counter, and herbal) and about any medical problems, including allergies. (If you're taking drugs for erectile dysfunction, be sure to mention them because these drugs can interact dangerously with some heart medications.)

How is a heart attack treated?

You'll be given oxygen to help your breathing, an I.V. will be started, and you will be placed on a heart monitor. A healthcare provider will perform a physical exam and order tests, including an electrocardiogram-a painless test that records the heart's electrical activity. Blood will be taken for lab tests. Results from these tests help decide whether you've had a heart attack and how to treat you.

You'll probably be given three medicines:

* nitroglycerin to increase blood flow to the heart

* aspirin to prevent blood clots from forming and blocking blood vessels

* morphine to ease pain and anxiety.

Depending on how long you've been having symptoms, you may receive a "clot-busting" drug to reopen the blocked blood vessel. Or you may need a procedure such as cardiac catheterization and angioplasty to open the blood vessel, or bypass surgery to restore blood flow to the affected part of the heart.

What can I do to prevent another heart attack?

Your healthcare provider will talk with you about lifestyle changes you can make to keep your heart healthy. You'll be referred to a cardiac rehabilitation program and a support group, if you need one. Follow these recommendations to reduce your risk of another heart attack:

* Stop smoking. Nicotine causes blood vessels to narrow, which could lead to another heart attack.

* If you have high blood pressure or diabetes, follow your healthcare provider's plan to keep your blood pressure, blood sugar, and weight under control.

* Eat a diet low in saturated fat and cholesterol.

* If you drink alcohol, limit yourself to one drink per day for women or two per day for men.

* Exercise regularly. Your healthcare provider can help you find the right exercise plan for you.