Can You Have a Heart Attack Without Knowing It? Learn the Signs of a Silent Heart Attack

When you think of a heart attack, you might imagine a very dramatic event. Sudden chest pain, profuse sweating, and shortness of breath are the typical signs that something is wrong with your heart. While some heart attacks may look like this, about one in five heart attacks are “silent.” This means that the person may experience few or no symptoms. But there are still warning signs to watch for and steps you can take to protect yourself.

What is a silent heart attack?

Just like any heart attack, a silent heart attack happens when the blood flow to part of your heart is blocked. That causes damage to the heart muscle. If not treated quickly, this damage can become permanent. 

The difference with a silent heart attack is that there are few, if any, noticeable symptoms. When symptoms do occur, they’re usually so mild or vague that they’re mistaken for other conditions.

Some examples include:

• A feeling of indigestion

• Unexplained fatigue

• Pain in your back, arm, neck, or shoulder

So, while the heart attack may not be completely silent, the symptoms can be misleading.

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Besides symptoms, is a silent heart attack the same as a regular heart attack? 

A lack of symptoms doesn’t mean a silent heart attack isn’t serious. It can have the same end results as a regular heart attack, such as: 

• Damage to your heart muscle

• Damage to your heart valves

• Heart rhythm abnormalities

• Congestive heart failure

• Sudden cardiac death

The consequences of a silent heart attack can even be worse than those of a typical heart attack. This is because someone having a silent heart attack may not get emergency care right away. 

Early treatment is critical for recovery — ideally within the first 6 hours. Since treatment is often delayed, heart damage from a silent heart attack is more likely to be permanent. 

Who’s at risk for silent heart attacks?

The risk factors for a silent heart attack are the same as those for any heart attack. The most common risks include:

• High blood pressure

• High cholesterol

• Diabetes

• Smoking

• Excess body weight

• Lack of regular exercise

• Age over 45 (for men) or 55 (for women)

Certain conditions increase your risk of having a silent heart attack. These include:

• Diabetes

• Surgery, especially in people over 65

• Critical illness of any type

• Covid-19 infection

• Sleep apnea

• Previous heart attack

• Age over 65

• Male sex

How can you tell if you’ve had a silent heart attack?

As mentioned above, a silent heart attack may cause symptoms that feel like something else. This can include indigestion, a cough, or upper body pain. But often, the symptoms of a silent heart attack show up in the days and weeks after it happens. 

Common symptoms include:

• Unexplained shortness of breath

• Decreased exercise tolerance

• Severe fatigue

• Swelling in your legs or abdomen 

• Dizziness

What should you do if you think you’ve had a silent heart attack?

If you have new or worrisome symptoms, the best thing to do is go to the emergency room. You don’t need to be having chest pain to get your heart checked out. 

An ER professional will recommend an EKG test. This quick and easy test can usually spot something abnormal. But it’s important to know that an EKG isn’t always accurate. Additional tests may be necessary, including:

• An echocardiogram

• A chest X-ray

• A CT scan

• Blood tests

Once you leave the ER, it’s important to follow up with your primary care provider. Other tests — like a stress test or catheterization — might be needed to figure out where your symptoms are coming from.

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Written by:

Sarah A. Samaan, MD

Sarah Samaan, MD, FACC, FACP, FASE is a board-certified cardiologist who practiced clinical cardiology for nearly 30 years. She is a member of the American College of Cardiology, the American College of Physicians, and the American Society of Echocardiography.

Edited by:

Katie E. Golden, MD

Katie E. Golden, MD, is a board-certified emergency medicine physician and a medical editor at GoodRx.

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