Do you know the symptoms of a heart attack? Would you know what to do if you are having a heart attack? Do you even know if you are at risk?

If you answered “no” to these questions, you’re not alone. A recent Cleveland Clinic survey revealed that the majority of Americans know very little about their heart health.

That attitude can be deadly: Heart attacks cause more deaths in the United States every year than all forms of cancer combined. Yet coronary artery disease — the disease that causes heart attacks — is largely preventable.  The good news is that the steps to prevent heart disease are the same measures that can lower your risk of heart attack. But you have to care.

“If you don’t know your risk for heart disease, you cannot take steps to prevent it,” says Steven Nissen, MD, Chairman of Cardiovascular Medicine at Cleveland Clinic.

Here are key things you need to know:

Know how a heart attack happens

Spaghetti-thin arteries on the outside of the heart muscle feed the organ with freshly oxygenated blood. If these arteries get clogged with fatty deposits, blood flow to the heart slows down. If a blood clot completely blocks the flow, a heart attack occurs.

Know the symptoms of heart attack

Heart attack symptoms can be vague and can be different in women than in men. “The vast majority of both sexes feel a gripping pain in the center of their chest that often radiates to the left arm, both arms or jaw. The sensation is often accompanied by shortness of breath or nausea,” Dr. Nissen says.

Know what to do if you have a heart attack

If you experience symptoms that might be a heart attack, and the discomfort lasts more than five minutes, call 911. While you are waiting for the ambulance, chew an aspirin to help break up the blood clot.

“Do not attempt to drive yourself to the hospital, and do not wait for someone else to drive you. These will only delay lifesaving care,” Dr. Nissen says.

“Likewise, do not call your physician for approval. The emergency department will call your physician for you.”

Know the difference between a heart attack and cardiac arrest

Only 13 percent of survey responders knew the difference between heart attack and cardiac arrest. Only 14 percent of men and 6 percent of women knew that electricity keeps the heart beating. Cardiac arrest is an electrical malfunction that causes the heart to beat wildly out of control.

When the heart beats too fast, it begins to quiver and is unable to pump, causing the person to pass out and collapse. Death will occur in minutes, unless action is taken to restore normal rhythm.

Know what to do in a cardiac arrest

Immediate cardiopulmonary resuscitation can make the difference between life and death, doubling or even tripling the person’s chance of survival. If you see someone collapse, check for a pulse. If the person is unconscious and has no pulse, start CPR.

Only 54 percent of survey responders knew CPR, and only 15 percent knew how to perform it correctly. Today, CPR is performed with only chest compressions. Only 11 percent knew how fast the chest compressions should be performed.

CPR is used to keep blood flowing until the heart’s proper rhythm can be restored with shock paddles, which are called defibrillators. Many public places and businesses have automated external defibrillations (AEDs) for this purpose. The good news is that 88 percent of people who have an AED in their work place know where it is located: 68 percent know how to use it.

“Today’s AEDs are very advanced,” Dr. Nissen says. “They will analyze the patient’s heart rhythm and only deliver a shock if it’s appropriate.”

Know your own risk for heart disease

Half of the survey responders said they knew very little about their own heart health. This is like playing Russian roulette with your health.

“Ignorance won’t make the problem go away,” Dr. Nissen says.

Don’t wait for your doctor to tell you whether you have heart disease, as 87 percent of Americans do. Raise the issue yourself. Don’t know what to ask? Thirty-seven percent of survey responders said they didn’t know either.

Here is what to do: Ask your doctor to measure your blood pressure, blood sugar and LDL cholesterol levels. Also, ask your relatives if anyone in the family might have had a heart attack or stroke, and note their age and gender.  Give this information to your doctor at your next visit.

The combination of your family history and risk of high blood pressure , also known as hypertension, diabetes and high cholesterol will help your doctor determine your individual risk for heart disease. With this knowledge, your doctor can recommend the medications or lifestyle changes you need.

“The fact that 56 percent of men in our survey knew more about their favorite sports team than heart disease prevention was surprising, but it’s not funny,” says Dr. Nissen. “If you’d like to enjoy your family, friends and favorite activities for many years, we advise you learn about your heart risk and take steps to lower it.”