Every year, an estimated 735,000 Americans have a heart attack, according to the Centers for Disease Control and Prevention.

A heart attack occurs when blood flow to the heart is significantly or completely halted — usually by a blood clot that forms after plaque in a coronary artery ruptures.

Plaque is made up of low-density lipoprotein (LDL) cholesterol, fats, and other waste products. When a hard plaque bursts, a blood clot forms quickly. If the clot is big enough, it will disrupt blood flow to your heart. Heart tissue that goes too long without oxygenated blood will die, placing you at higher risk for heart failure and other complications.

While the heart attacks you’ve seen in movies and television usually involve a person clutching their chest in pain, there may be other symptoms too, such as shortness of breath or lightheadedness. Many experience a wide range of symptoms.

Men and women often experience different symptoms, according to the American Heart Association.

The way a heart attack feels to you may be much different from how it felt for someone else. You may be able to carry on a conversation or finish a meal. But you will probably know that something is wrong, even if you don’t have a sudden pain in your chest or feel on the verge of passing out (another symptom).

If you suspect you or someone close to you is having a heart attack, call 911. Don’t try to drive yourself to the hospital if you have heart attack symptoms. The sooner you get treatment and have regular blood flow restored, the less damage that may occur to heart tissue.

The classic symptom of chest pain may not be present in every heart attack, but it remains the most common sign among men. The pain is often described as a pressure or squeezing sensation. Chest pain tends to be located in the center of the chest, but it can be felt from armpit to armpit.

Other common heart attack symptoms for men include:

  • shortness of breath, which sometimes develops before any other symptoms, and may be present when sitting still or moving around
  • back pain, often moving up to the neck
  • arm pain, typically in the left arm, but can be in either or both arms
  • jaw pain that sometimes feels like a bad toothache
  • nausea
  • sudden cold sweat
  • lightheadedness or dizziness

The most common symptom of heart attack in women is chest pain or tightness. Women may also experience pain in the upper abdomen. Women are also more likely than men to experience nontraditional symptoms, such as:

  • fatigue, which may appear for several days prior to other symptoms and create the impression you have the flu rather than a heart attack
  • upper back pain that may feel like burning, tingling, or pressure
  • neck and jaw pain — often without any chest pain (jaw pain can coincide with a heart attack because the nerves that serve the heart and those that serve the jaw are close together)
  • pain, tingling, or discomfort in either or both arms
  • nausea and vomiting
  • shortness of breath, with or without chest pain that can come on suddenly (as though you just finished running without having been moving at all)

Because certain symptoms, such as nausea or fatigue, can signal any number of health concerns or illnesses, you should be particularly mindful of other possible heart attack symptoms.

If you suddenly become nauseated and you’re having trouble catching your breath or you’re feeling serious jaw pain, call 911. Tell the operator you may be having a heart attack.

Women are often reluctant to seek medical attention for heart attack symptoms. While women are slightly less likely than men to have heart attacks prior to menopause, the odds essentially are equal after menopause.

To make matters even more complicated, some heart attacks occur without any traditional symptoms, or even any noticeable symptoms at all. These so-called silent heart attacks could represent as many as half of all heart attacks in the United States.

A silent heart attack may resolve on its own if, for example, the clot blocking blood flow dissolves or becomes dislodged and is absorbed into the body. But a silent heart attack can still cause some damage.

If a doctor discovers that you had a silent heart attack, you should consider cardiac rehabilitation and the type of care that any other person who’s had a heart attack receives.

A silent heart attack may be discovered months or years after the fact if you have an electrocardiogram (EKG) to check the heart’s electrical system. Evidence of a heart attack can often be seen in the electrical patterns picked up by the EKG.

Initial heart attack symptoms, including chest pain and shortness of breath, may come and go. Symptoms often last around 10 minutes or longer.

A study published in Critical Pathways in Cardiology found that symptoms lasting less than five minutes are unlikely to indicate a heart attack, while symptoms lasting longer than five minutes should be taken seriously as signs of a myocardial infarction (the clinical term for a heart attack).

However, this finding comes from only one study. So if you have symptoms lasting longer than a few minutes, you need to call 911.

Even though a heart attack is a sudden event, some symptoms can come on mildly and slowly.

You may feel unusually tired for a few days leading up to the onset of more serious symptoms. Some who’ve experienced a heart attack report feelings of anxiety and dread for a few days too.

Mild-to-moderate pain in one or both arms, along with shortness of breath and nausea, may also occur in the lead-up to a major heart attack.

You should also understand your heart attack risk prior to an actual event. If you have any of the following risk factors, you should be especially mindful when symptoms appear:

Calling 911 or having someone drive you to an emergency room for a suspected heart attack may seem like a drastic step, especially if you’re not sure what’s happening. But it’s better to be evaluated and given a clean bill of health than chance the greater harm from a heart attack that goes untreated.

Symptoms that feel like a heart attack may also signal other conditions. An anxiety attack, for instance, can result in chest pain, shortness of breath, and sweating. Although an anxiety attack may not be life-threatening, it should still be evaluated.

You shouldn’t ignore symptoms that feel like a heart attack. Those who’ve had a heart attack often describe a vague feeling of uneasiness or even doom that they can’t explain. Trust your instinct and pay attention to all the signs your body is sending you.