A heart attack (also known as a myocardial infarction) occurs when the flow of blood to an area of the heart is blocked, often because of a buildup of substances like fat or cholesterol.
A heart attack is a potentially life-threatening medical emergency that can lead to cardiac arrest or death. Heart attacks are common, too, with an estimated 805,000 people in the United States having a heart attack each year, or about one person every 40 seconds, according to the Centers for Disease Control and Prevention (CDC).
To act quickly to seek emergency medical care, it’s important to be able to recognize the warning signs of a heart attack.
A heart attack (also known as a myocardial infarction) occurs when the flow of blood to an area of the heart is blocked, often because of a buildup of substances like fat or cholesterol. If blood flow isn’t quickly restored, heart tissue in this area can start to die. This can reduce or even stop the blood flow to other areas of the body.
A heart attack is a medical emergency that can be life-threatening. In a 2019 study of older adults in the United States, researchers estimated that about 12% of people hospitalized for a heart attack died within 30 days.
In movies and TV, you’ll often see a person clutching at their chest while having a heart attack. While chest pain (also known as angina) can be a common symptom of a heart attack, there are several others that are important to know about, including:
Pain, discomfort, tightness, pressure, or heaviness in the chest
Pain or discomfort in other areas like the arms, shoulders, back, neck, or jaw
Indigestion or heartburn
Shortness of breath
Dizziness or lightheadedness
Nausea or vomiting
A cold sweat for no clear reason
Extreme fatigue that can’t be explained by other causes
Anxiety
Quick or uneven heart rhythms
A heart attack is caused by a lack of oxygen-rich blood flow to the heart’s muscle tissue. When any tissue in our body lacks oxygen, it begins to die. Heart tissue that has died can no longer work properly to pump our blood.
The most common cause of heart attacks is coronary artery disease (CAD). CAD is the most common type of cardiovascular disease in the United States, impacting roughly one in 20 adults aged 20 and over.
In CAD, the coronary arteries that send oxygen-rich blood to our heart become narrowed due to the presence of plaque ion their walls. The medical term for this buildup is atherosclerosis. Sometimes, plaque can break off from the artery wall. When this happens, a blood clot can form that blocks the coronary artery, impeding blood supply and leading to a heart attack.
Other potential causes of a heart attack may include:
A coronary artery embolism, which is when a blood clot from another part of our body that travels to and blocks a coronary artery
A sudden tightening, or spasm, of a coronary artery
A rupture, called a dissection, that forms within a coronary artery
There are certain things that can boost a person’s risk of having a heart attack, referred to as risk factors.
Some of the factors that increase the risk of a heart attack are completely out of an individual’s control. For example, heart attack risk increases with age. In fact, most heart attacks occur after age 45 for men and after age 55 for women, according to the National Heart, Lung, and Blood Institute.
Family history can also play a role in our heart attack risk. When you have a family history of early CVD, your risk of heart disease — including heart attack — is increased.
Having certain other health conditions can increase our risk of heart attack as well. These include:
High blood pressure
High triglycerides or cholesterol levels
High blood sugar or diabetes
Overweight or obesity
Lastly, some lifestyle habits may elevate the risk of heart attack. These include:
Smoking
An unhealthy diet, particularly one that’s high in saturated or trans fats, cholesterol, or sodium (salt)
A lack of physical activity, often called a sedentary lifestyle
If it seems like someone is having a heart attack, it’s important to get emergency care quickly by calling 911. Many heart attacks are diagnosed and treated in the emergency department of a hospital.
One of the first tests that may be done if a heart attack is suspected is an electrocardiogram (ECG). This is a test that measures the electrical activity of the heart.
An ECG records electrical impulses when the heart beats, creating a wave pattern that a doctor can evaluate. This can tell a doctor how fast and intense the impulses are, giving them an indication of how well the heart is working.
Blood tests may also be ordered. These use a sample of blood from a vein in the arm and can measure markers, such as cardiac troponin, that signal whether the heart has been damaged.
Imaging tests like a chest X-ray or CT scan can also be done to look at the heart and check for complications. However, because a heart attack is a medical emergency, imaging tests may be done after treatment has already started.
When a heart attack is suspected, every second counts. Because of this, doctors may begin emergency treatment even before testing confirms a heart attack.
The first emergency treatments done when a heart attack is suspected can include:
Aspirin to prevent additional blood clots
Nitroglycerin to open the arteries and improve blood flow
Thrombolytic medications, also called clot busters, that help break up blood clots
Oxygen therapy to boost blood oxygen levels
Beta-blockers to slow heart rate so the heart can recover
Statins to stabilize plaque in the heart's blood vessels and reduce cholesterol
A variety of procedures may be done in the hospital to help restore blood flow in the heart. One option is angioplasty, though percutaneous coronary intervention (PCI) is the preferred way to do this.
During a PCI, a doctor uses imaging to guide a thin, flexible tube called a catheter to the blood vessels in the heart. A special type of dye helps the doctor to find the blockage.
A balloon attachment at the end of the catheter may then be inflated to open up the blocked artery. A small mesh tube called a stent is often put in place to help keep the artery open.
It takes time to recover after a heart attack. Your doctor will let you know when you can safely return to regular activities.
During recovery, steps also can be taken to help prevent another heart attack from happening. These typically include medications and heart-healthy lifestyle changes.
Recovery from a heart attack can also involve cardiac rehabilitation, which is a program aimed at helping with recovery from heart problems. According to the CDC, cardiac rehab typically involves:
Physical activity
Guidance on taking medications as prescribed
Education on heart-healthy lifestyle changes
Help to quit smoking
Counseling to improve mental health and help lower stress
It’s also important to know that having a heart attack can cause lasting heart damage. This can lead to long-term complications like heart failure and arrhythmias that will need to be managed as well.
Heart attacks are serious, but the good news is that they’re very preventable. In fact, the World Health Organization (WHO) notes that 80% of early deaths due to heart attack or stroke can be prevented by reducing tobacco use, eating a healthy diet, and increasing physical activity.
Heart attack prevention centers on reducing risk factors that you can actively change, which are those related to your lifestyle. Following the tips below can not only help to prevent a heart attack but also promote heart health and improve overall health:
Quit smoking. Research has found that quitting smoking is associated with a significantly lower risk of CVD in people who were formerly heavy smokers compared to those who currently smoke. According to the American Heart Association, you will cut your risk of coronary heart disease by 50% just a year after you quit.
Eat a healthy diet. A healthy diet is generally one that’s high in fruits and vegetables, whole grains, low-fat dairy, and leaner protein sources.
Reduce intake of certain foods. Foods that are high in saturated or trans fats, cholesterol, salt, and added sugars can increase our risk of CVD. Limiting your intake of those foods is a helpful preventative measure to take.
Stay physically active. The Physical Activity Guidelines for Americans recommends getting at least 150 minutes of moderate-intensity physical activity (or 75 minutes of vigorous activity) each week, in addition to two days of strength training activities.
Manage weight. Carrying excess weight or having obesity is a risk factor for CVD as well as other conditions like diabetes and high blood pressure. A doctor can recommend healthy ways to lose weight.
Get enough sleep. Some research has linked short sleep duration and poor sleep quality to CAD, the main cause of heart attacks. Experts typically recommend that adults get seven to nine hours of sleep every night.
Take steps to lower stress. Stress is a known risk factor for conditions that increase the risk of heart attack, including diabetes, high blood pressure, and obesity. Ways to lower your stress levels include talking to a therapist or engaging in mindfulness techniques like meditation.
Limit alcohol. While there is a lot of variation, research has generally found that alcohol consumption is associated with a higher risk of CVD.
Address other health conditions. It’s important to work with your doctor to manage other health conditions that can increase your heart attack risk, such as diabetes, high cholesterol, and high blood pressure.
While you can take steps in your daily life to prevent heart attack, it’s still possible to experience one. If you’re concerned that you or another person is experiencing symptoms of a heart attack, call 911 immediately.