Heart disease is our country’s leading cause of death, claiming close to 610,000 lives each year. In fact, roughly every 40 seconds, someone in the U.S. has a heart attack, and many are fatal.

People often assume they’ll know when a heart attack hits, expecting crippling chest pain or pain that travels down the left arm. But not every heart attack is accompanied by these “classic” symptoms. Approximately 15-20% are considered “silent” heart attacks.

What is a silent heart attack?

A silent heart attack happens when less obvious heart attack symptoms either aren’t felt or aren’t recognized.

These silent heart attack signs include:

Lightheadedness

Shortness of breath

Nausea

Vomiting, indigestion or other gastrointestinal distress

Severe fatigue

Sweating

In my practice, people who survive a silent heart attack often report they ignored one or more of the above symptoms, or they attributed the symptoms to something else. They may have thought vomiting and severe fatigue were caused by a viral infection. Or, they may experience new shortness of breath while climbing stairs but just assume they need to exercise more. People with compromised pain perception (such as the elderly or those with diabetes) are also more likely to miss these subtle symptoms.

Silent heart attacks are not generally noted until the patient’s next routine electrocardiogram (EKG), which will show the characteristic markings of a prior heart attack. In more unfortunate circumstances, a silent heart attack may not be detected until a second heart attack sends the person to the hospital.

How you can avoid a silent heart attack

To prevent a heart attack, it’s important to know your risk. See your doctor regularly and answer honestly and completely when he or she asks questions about your medical history, your family’s medical history, your behaviors, and your lifestyle choices.

Factors that increase your heart attack risk include diabetes, smoking, high blood pressure, high cholesterol, a strong family history of heart disease, and a sedentary lifestyle. If you’re at greater risk of having a heart attack for any of these reasons, you should seek evaluation from a medical professional.